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[ J . F. I.,

T h e g r o w i n g i m p o r t a n c e of a b r a s i v e s is s u c h as to sugg e s t inquiry concerning our f u t u r e supply. A t present, w e depend, for the larger part of this, on r e m o t e foreign lands. Practically on one land, for the e m e r y - b e a r i n g G r e e k islands lie so close to t h e coast of A s i a Minor t h a t they are geographically T u r k i s h and only politically Greek. T h e ore all passes t h r o u g h a few ports, and the ever u n s e t t l e d Eastern q u e s t i o n m i g h t at a n y time p r e c i p i t a t e a war, and t h e blockade of these ports. T h e Encyclopcedia Britannica mentions the occurrence of e m e r y in Sweden, Spain, S a x o n y and Greenland, b u t T u r k e y and Greece are, apparently, the only foreign- countries which afford a c o m m e r c i a l supply. T h u s far our s u p p l y of native e m e r y has come from N e w York and M a s s a c h u s e t t s , while t h e c o r u n d u m has c o m e from P e n n s y l v a n i a , N o r t h Carolina and Georgia. S o m e hope of n e w sources is s u g g e s t e d b y the h u m o r i s t a l r e a d y quoted, w h o says that e m e r y is " s c a t t e r e d over m o r e or less all the earth," and also b y the s t r e a m of letters which, for y e a r s past, has flowed in upon w h e e l and e m e r y ~makers, offering c o r u n d u m m i n e s from W a s h i n g t o n , on our northw e s t coast, to S o u t h Carolina, on t h e southeast. [To be concluded.]

ENGINEERING

PRACTICE

AND E D U C A T I O N . *

By GArtWAteO LA•ZA, S. B., C. & M. E., Professor of Theoretical and Applied Mechanics, Massachusetts I n s t i t u t e of Technology.

If any one a m o n g m y heare÷s expects m e to b e g i n this lecture b y g i v i n g a definition of the w o r d s Engineering and L'ngineer, I am afraid he will be disappointed. Definitions are a t t e m p t s to describe, or to give the d i s t i n g u i s h i n g characteristics of the t h i n g defined, in a v e r y few words. T o give t h e m is c o m p a r a t i v e l y e a s y w h e n t h e things defined are of limited scope ; b u t the more e x t e n d e d the scope, t h e A series of six lectures prepared for delivery in the Lowell Institute, in Boston, Mass.; the last t h r e e of w h i c h were n o t given on account of t h e sickness of t h e Author.

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more difficult does it b e c o m e to circumscribe them within the b o u n d s of a definition. Indeed, the term Engineering has b e e n used with different significations at different times, and w h a t has b e e n its accepted m e a n i n g at any one time has d e p e n d e d u p o n the particular condition of the world's industrial progress at t h a t period. W i t h o u t g o i n g into a g r e a t m a n y details, I m a y say that the definition of the profession of t h e Civil Engineer, a d o p t e d by. t h e Council of the British I n s t i t u t i o n of Civil Engineers, in r828, was, " the art of directing the g r e a t sources of p o w e r in N a t u r e for the use and c o n v e n i e n c e of man." Such a definition as this is n o t only vague, but, if taken literally, it w o u l d include a range of work far m o r e extensive than t h a t w h i c h has ever b e e n or is n o w u n d e r s t o o d as t h e province of the engineer. N e v e r t h e l e s s , the converse is true of the e n g i n e e r (omitting the l i m i t i n g term civil), i. e., the e n g i n e e r must, in the practice of his profession, direct the g r e a t sources of p o w e r in N a t u r e for the use and convenience of man. A t one time, w h e n the science of e n g i n e e r i n g was still q u i t e limited in its scope, there were only t w o d e s i g n a t i o n s used, viz.: m i l i t a r y e n g i n e e r i n g and civil engineering, the l a t t e r term d e n o t i n g all e n g i n e e r i n g which was not military. L a t e r on, as the science, and hence the scope of engineering, advanced, and as engineers b e g a n to devote themselves to special lines of work, there arose a large v a r i e t y of designations, s o m e of w h i c h are : civil e n g i n e e r i n g (no longer used in the original sense), mechanical engineering, m i n i n g engineering, etc., and it was a s s u m e d t h a t these professions were q u i t e distinct from each other. Indeed, this idea s e e m e d to be in accord w i t h the n a t u r a l drift t o w a r d s specialization, and in the line of progress. Now, however, that the t e n d e n c y t o w a r d s specialization is ever on the increase, and t h a t p r o g r e s s has gone farther, I think t h a t any one w h o will e x a m i n e the facts carefully, and in a judicial frame of mind, will be satisfied that while all these different kinds of engineers are a p p l y i n g their art to a specialty, n e v e r t h e l e s s , the art is one, and the functions

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of the e n g i n e e r comprise one definite, t h o u g h wide a n d extensive, range of work. W e will now proceed to consider some e x a m p l e s of t h e e n g i n e e r i n g works of the world of different kinds, in s u e h detail as our time will allow ; a n d w h e n we h a v e d o n e this, w h e t h e r we do or do not a t t e m p t to f o r m u l a t e a definition t h a t will describe the f u n c t i o n s of the e n g i n e e r of to-day and of the f u t u r e , we shall, at any. rate, realize and unders t a n d b e t t e r w h a t is the range, w h a t are the kinds, a n d w h a t is the character of t h e work w h i e h it is the b u s i n e s s of t h e e n g i n e e r to p e r f o r m for his fellow-men. P a s s i n g by the p y r a m i d s and the works of the E g y p t i a n s and of the E a s t e r n nations, it will be w o r t h our while to consider for a s h o r t t i m e w h a t was the e h a r a e t e r of the e n g i n e e r i n g work of a n c i e n t R o m e . And, a l t h o u g h t h e d e v e l o p m e n t of such work was v e r y different at different periods of the l o n g centuries d u r i n g w h i c h R o m e held her s w a y over the Old World, it will not be n e c e s s a r y for me to trace its various phases, for, i n a s m u c h as the s t e a m e n g i n e h a d not y e t been t h o u g h t of, it was n o t possible for a d v a n c e s to be m a d e at such a rapid rate as t h a t w i t h w h i c h t h e y are developed in our own times. Moreover, a c o n s i d e r a t i o n of the e n g i n e e r i n g work of a n c i e n t R o m e gives us a conception of t h a t of the whole civilized world as it t h e n e x i s t e d ; for R o m e carried her civilization a n d her e n g i n e e r i n g everyw h e r e in the wake of h e r victorious arms. Indeed, it was very l a r g e l y to t h i s cause t h a t was due tile firm grip t h a t she acquired over the n a t i o n s t h a t she conquered. T h e y found t h a t t h e i r conquerors offered t h e m a civilization more a t t r a c t i v e t h a n t h e i r own, and t h a t R o m e really took an i n t e r e s t in d e v e l o p i n g their countries, m a k i n g good roads conffeeting t h e m w i t h herself, a n d s e n d i n g h e r own engineers to aid t h e m in m a k i n g other roads and local i m p r o v e m e n t s , besides e n c o u r a g i n g t h e m to develop their n a t u r a l resources. ~l'he i n t i m a t e connection into which t h e y were t h u s b r o u g h t w i t h her led t h e m to i n t r o d u c e such i m p r o v e m e n t s as t h e y f o u n d t h a t the R o m a n s possessed. H e n c e we find t h a t R o m a n roads, R o m a n bridges, R o m a n a q u e d u c t s and R o m a n sewers spread to all parts of

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Europe, and to all countries w h i c h came under her domination. T h e n w h e n the d a y s of corruption came and w h e n she no longer chose to keep herself in the rank of the producers of the world, b u t s o u g h t to be fed by others w i t h o u t m a k i n g any a d e q u a t e r e t u r n ; w h e n she no longer took pains to do t h o r o u g h work, the R o m a n example of f o r m e r times, which had a l r e a d y p e r m e a t e d the other c o u n t r i e s of the Empire, still exercised its influence; and hence it is that some of the m o s t l a s t i n g and best examples of R o m a n works were to be found in Gaul, in Spain and in Africa. W h e n we stop to consider h o w t h e y m a n a g e d to accomplish w o r k s of such m a g n i t u d e and of such merit as they did w i t h the small a m o u n t of facilities t h a t t h e y possessed, it s e e m s t r u l y wonderful. I m a g i n e for a m o m e n t What would be the aspect of the world, and w h a t the material welfare of our own land, if we were to annihilate the use of s t e a m and of all the m a c h i n e r y that d e p e n d s on s t e a m engines to o p e r a t e it. A n d y e t the R o m a n s h a n d l e d and t r a n s p o r t e d e n o r m o u s weights, w h i c h w o u l d even m a k e us stop to consider h o w b e s t to h a n d l e them. W h e n t h e y had to carry some of their e n o r m o u s monoliths long distances over land, t h e y encased t h e m in cylindrical w o o d e n boxes, and rolled these boxes along the . ground, d r a w i n g t h e m b y m e a n s of a v e r y large n u m b e r of horses ; then, for lifting them, the m e a n s t h e y possessed were tackle, rollers, screws and wedges. T h e i r s t o n e - c u t t i n g had to be p e r f o r m e d b y m a n u a l labor, the use of fire and v i n e g a r b e i n g only applicable to certain kinds of stone, and even then b e i n g hardly ever employed, and no o t h e r b l a s t i n g c o m p o u n d s b e i n g k n o w n at that time. On t h e i r roads, however, were often to be found large n u m b e r s of t u n n e l s c u t wholly or partially t h r o u g h solid rock ; some of their tunnels were of g r e a t Length, as, for instance, the t w o tunnels at Posilipo, and also the emissary of Lake Fucino, the latter b e i n g a wonderful piece of e n g i n e e r i n g c o n s i d e r i n g the facilities that t h e y could command, notw i t h s t a n d i n g its failure to accomplish its object. Moreover,

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t h e y often w e n t so far as to dress the stone on the sides of t h e i r tunnels. T h e R o m a n roads I shall not stop to deseribe, f u r t h e r t h a n to say that, while, from our p o i n t of view, t h e y were decidedly narrow, t h e y were b u i l t w i t h an a m o u n t of solidity t h a t is surprising, a n d an a m o u n t of labor was e x p e n d e d u p o n t h e m which is very creditable to t h e i r m a k e r s ; moreover, the n u m b e r and e x t e n t of these roads c o n n e c t i n g all parts of the E m p i r e w i t h R o m e was s o m e t h i n g e n o r m o u s for those days. W h i l e t h e y k n e w and used m o s t of the m e t a l s on a small scale, thq principal m a t e r i a l s e m p l o y e d in t h e i r engineeri n g work were stone, bricks and cement, t h o u g h some of their bridges were b u i l t of wood ; and of course works of an i n t e n t i o n a l l y t e m p o r a r y c h a r a c t e r were often c o n s t r u c t e d of timber. On a c c o u n t of t h e difficulties of t r a n s p o r t a t i o n the materials for b u i l d i n g were o b t a i n e d as n e a r the place w h e r e t h e y were to be used as possible; hence, w h e n available, stone was derived from local sources, a n d this led to t h e e s t a b l i s h m e n t of quarries at a g r e a t m a n y places all over the Empire, the q u a r r y i n g b e i n g performed, however~ b y m a n u a l labor, w i t h a v e r y occasional use of fire a n d v i n e g a r . For t h e i r l a r g e r vc~rks, their bricks were well. b u r n e d ; b u t the cost of fuel f r e q u e n t l y led t h e m to b u i l d houses of bricks dried in the sun. Next, as to c e m e n t : w h e n e v e r t h e y could find s u i t a b l e m a t e r i a l s n e a r by, t h e y used them, otherwise t h e y s e c u r e d it from f u r t h e r off. T h e y h a d at Pozzuoli, near Naples, however, the source of s u p p l y w h e n c e t h e y o b t a i n e d t h e i r f a m o u s puzzolana, and this was s e n t w h e r e v e r needed, b e i n g t r a n s p o r t e d by w a t e r to t h e n e a r e s t point accessible by t h a t means, and t h e n c e b y land. T h e R o m a n b r i d g e s and v i a d u c t s were either of wood or stone. In the case of the l a t t e r the full centre a r c h w a s a l m o s t exclusively used. W h e n t h e y could locate the f o u n d a t i o n s of their stone b r i d g e s on dry land, t h e y b u i l t good and solid s t r u c t u r e s ; b u t w h e n t h e y h a d to.lay t h e i r f o u n d a t i o n s u n d e r water, t h e y always h a d difficulty, and these were g e n e r a l l y w a s h e d a w a y . i n a short time, n o t w i t h s t a n d i n g the v a r i e t y

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of e x p e d i e n t s to which t h e y h a d recourse. H e n c e we find t h a t there were b u t few R o m a n b r i d g e s across wide streams, w h e r e f o u n d a t i o n s in the river w e r e necessary, b u t they had no difficulty in crossing deep and narrow g o r g e s where they could establish solid f o u n d a t i o n s for their work. T h e y had no m e a n s of w o r k i n g u n d e r water, or of laying foundations u n d e r a considerable d e p t h of water, and w h e n t h e y tried t h e y did n o t " s u c c e e d to m a k e t h e m sufficiently secure. T h e i r a q u e d u c t s and sewers were fine s p e c i m e n s of engineering, considering the facilities t h e y possessed. The w a t e r s u p p l y from different sources was k e p t separate, the p u r e s t b e i n g u s e d for drinking. T h e i r a q u e d u c t s were g e n e r a l l y m a d e of m a s o n r y or concrete, lined with a mixture of c e m e n t and b r i c k d u s t polished smooth. T h e y carried these a q u e d u c t s across gorges or valleys, on stone b r i d g e s or viaducts, s o m e t i m e s b u i l t of two or three rows of arches, one above the other, and this m e t h o d t h e y p r e f e r r e d to t h e use of siphons, t h o u g h t h e y had recourse to siphons at times, and, at times t h e y e m p l o y e d a c o m b i n a t i o n of the two methods. T h e y also u s e d settling tanks to clarify the w a t e r b y allowing the i m p u r i t i e s to deposit. Besides m a s o n r y conduits, t h e y u s e d lead pipes, b u t t h e y h a d no pipes t h a t could b e a r a v e r y h e a v y pressure. T h e y had no n~eans of pumping, and hence the w a t e r had to be b r o u g h t to the place w h e r e it was to be used b y gravity. T h e sewers were, of course, a necessary conseq u e n c e of the w a t e r supply, and t h e s e ran at one time u n d e r e v e r y street in R o m e ; b u t after the r e c o n s t r u c t i o n of the streets b y Nero, the lines of the streets did not a l w a y s follow the lines of the sewers, and hence sewers often p a s s e d u n d e r the houses. T h e earlier sewers were cons t r u c t e d of c u t stone, and so solidly were t h e y built that the Cloaca M a x i m a can still be seen to-day, although t h e g r e a t e r p a r t of it is filled up with earth. T h e pitch of the sewers was small, however, and hence t h e y were easily choked up. Moreover, a g r e a t m a n y cities in different p a r t s of t h e E m p i r e were p r o v i d e d with s y s t e m s of w a t e r supply a n d drainage. T a k i n g up next the ports and the waterways, we find that,

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t h e i r b o a t s being small, the works t h a t t h e y needed, and t h a t t h e y therefore executed, w o u l d not look large from our m o d e r n point of v i e w ; but, considering the times, some of t h e m were magnificent pieces of engineering. As to ports, w h e n t h e y could t h e y built t h e m in a river, e r e c t i n g q u a y s of stone or wood. T h e y took a d v a n t a g e of. the shelter afforded b y n a t u r a l features, and b u i l t protecting b r e a k w a t e r s w h e n t h e y n e e d e d them. W h e n t h e y could reach d r y land to b u i l d upon t h e y always did so, b u t w h e n not, t h e y sunk large stones, or ~ cradles filled, with masonry, locating t h e m b y m e a n s of divers, or else t h e y b u i l t dikes, and ran in liquid concrete, which, on solidifying, formed, as it were, a solid rock. T h e y had a g r e a t m a n y ports all along the Mediterranean. T h e y had, however, no efficient s y s t e m of dredging, and t h e i r ports were always silting up. Of,course, their n a v i g a b l e rivers formed the n a t u r a l commercial h i g h w a y s , as indeed t h e y did e v e r y w h e r e before the i n t r o d u c t i o n of ra{lroads; hence, t h e y carried o u t such i m p r o v e m e n t s as t h e y could, and such as were n e e d e d at t h e time, b y r e m o v i n g o b s t r u c t i o n s from t h e river beds and by. b u i l d i n g sea wails. T h e y also b u i l t a large n u m b e r of cabals, s o m e to connect t w o n a v i g a b l e rivers, some to c o n n e c t a river w i t h t h e sea, w h e n the c h a r a c t e r of its m o u t h was such as to render it difficult for b o a t s to e n t e r in r o u g h weather, and also to drain regions that were liable to be flooded in t i m e s of freshets. A p p a r e n t l y t h e y were familiar with t h e use of sluice-gates, b u t not w i t h the use of locks. N o t w i t h s t a n d i n g the fact t h a t t h e y h a d no efficient s y s t e m o f dredging, the canal b u i l t b y Claudius and T r a j a n to c o n n e c t the T i b e r w i t h the sea still forms the p r e s e n t n o r t h e r n b r a n c h of, t h e T i b e r ' s delta, a l t h o u g h all the works long ago silted u p ; moreover, it served to provision R o m e for four or five centuries. Similar c a n a l s ' w e r e b u i l t in the case of a large n u m b e r of o t h e r rivers e m p t y i n g into. the M e d i t e r r a n e a n a n d the Adriatic. O t h e r m e m o r a b l e canals e d n s t r u c t e d b y the ancients were the various ones b u i l t from time to time to c o n n e c t the Nile with t h e R e d Sea, and the one c o n n e c t i n g

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t h e port of Alexandria with t h e Nile, w h i c h was planned b y A l e x a n d e r and executed b y P t o l e m y . T h e R o m a n s operated mines, not only in Italy, b u t also in various portions of the Empire. In Italy itself it is on record t h a t there were gold m i n e s in the valley of the Aosta, t h a t there was galena in T u s c a n y , iron in Noricum, a n d t h a t the E t r u s c a n s w o r k e d iron in U m b r i a and Brutium. E l b a c o n t a i n e d iron mines, and does now; and Sardinia, leacl mines. A k n o w l e d g e of mining, however, preceded t h e t i m e s of the R o m a n conquests, and m i n i n g operations w e r e a l r e a d y u n d e r w a y in the c o n q u e r e d countries before t h e s u p r e m a c y of R o m e , b u t the R o m a n s w a y developed a g r e a t e r a c t i v i t y in them. Both Gaul and Spain were rich in mineral resources. T h e R o m a n s , and also the Greeks, learned the metallurgical p r o c e s s e s from the E g y p t i a n s and the races of the East. T h e R o m a n s u s e d gold in its native state, and hence it o f t e n c o n t a i n e d silver, copper, or even iron. T h e enormous q u a n t i t y of copper u s e d b y t h e m w o u l d seem to indicate t h a t t h e y f o u n d n a t i v e copper, or else c a r b o n a t e of copper. T h r o u g h o u t F r a n c e we find traces of old R o m a n iron works, in pries of slag and cinder, t h e s e works b e i n g at the mitres, in c o n s e q u e n c e of the difficulties of transportation. T h e i r condition in regard to m a n u f a c t u r e s , especially in t h e earlier days, was so p r i m i t i v e as to be h a r d l y w o r t h s p e a k i n g of. Such is a v e r y brief and c u r s o r y view of the state of e n g i n e e r i n g practice a m o n g the R o m a n s . W h i l e we look with the p r o f o u n d e s t r e s p e c t and a d m i r a t i o n at the works w h i c h t h e y a c c o m p l i s h e d with the smal! m e a n s at their c o m m a n d , and while those w h o e x e c u t e d t h e m deserve the h i g h e s t m e e d o f praise and all the h o n o r that we can give them, n e v e r t h e l e s s I w o u l d say to the p e s s i m i s t w h o thinks t h a t the world is always g o i n g from b a d to worse, go and try living w i t h such conveniences as were available in the old R o m a n times, the narrow streets, the u n c o m f o r t a b l e houses, the lack of facilities for travelling, the g r e a t lack of c o n v e n i e n c e s as c o m p a r e d with w h a t we possess to-day, and then see w h e t h e r y o u will not appreciate the g r e a t boon

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Lanza :

[J. F. I.,

t h a t all our modern civilization and i n d u s t r i a l progress h a s conferred upon us. T h e y possessed n e a r l y all the m a t e r i a l s of N a t u r e t h a t we possess, but t h e y h a d a c q u i r e d v e r y little control i n d e e d over t h e g r e a t sources of power in N a t u r e , and before t h e y could m a k e m u c h f u r t h e r progress in their e n g i n e e r i n g work, t h e y n e e d e d to be able to direct these for the use and convenience of man. T h i s was w h a t t h e y specially lacked. W i t h the exception of tile wind as used in s a i l i n g vessels, t h e y m a y be said to h a v e used m u s c u l a r power of m e n or of animals for the a c c o m p l i s h m e n t of all t h e i r work, and t h e i r history is a g r a n d e x a m p l e of w h a t m a n has been able to accomplish by the aid of little else in the w a y of power t h a n m u s c u l a r e n e r g y ; b u t w h e n t h e y w a n t e d to accomplish a very large task, t h e y h a d to use a v e r y large a m o u n t of t h i s p o w e r ; thus, in e x c a v a t i n g t h e t u n n e l u n d e r L a k e F u c i n o , it is said t h a t 30,0o0 w o r k m e n were e m p l o y e d for eleven years. In order to be able to m a k e a d v a n c e s in m a t e r i a l prosperity, and to s u r r o u n d h i m s e l f w i t h a l a r g e r s u p p l y of c o m f o r t s and conveniences, m a n n e e d e d s o m e t h i n g m o r e t h a n m u s c u l a r e n e r g y to aid h i m in his work. H e n e e d e d to m a k e t h e wind, the water, b u t more especially steam, his servants, and to secure the a d d i t i o n a l a d v a n t a g e s of industrial progress w h i c h could n e v e r h a v e been realized h a d it not been for the i n t r o d u c t i o n of the s t e a m engine, before h e could pass from such works as those of the R o m a n s to t h e m a g n i f i c e n t e n g i n e e r i n g a c h i e v e m e n t s of m o d e r n times. Indeed, we h a v e in this old R o m a n work a very good e x a m p l e of w h a t e n g i n e e r i n g science and enterprise was able to accomplish w i t h practically no aid from .nlachinery; and were I to trace, step by step, the progress of the world only in t h e kinds of work m e n t i o n e d , viz., roads, bridges, ports, waterways, w a t e r supply and drainage, you would be forced to the conclusion t h a t ' i t was by the i n t r o d u c t i o n of m a c h i n e r y , and of s t e a m power to move t h a t m a c h i n e r y , t h a t e v e r y point of v a n t a g e was gained, and every a d v a n c e was rendered possible. By w a y of illustration, we m a y note t h a t two of the g r e a t e s t difficulties which the R o m a n s e n c o u n t e r e d

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Engineering Practict and Education.

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were d u e to not h a v i n g the m e a n s of establishing secure f o u n d a t i o n s u n d e r water, and not h a v i n g any such means of d r e d g i n g as weXlaave to-day. I shall not undertake, however, to trace the decadence of e n g i n e e r i n g practice through t h e dark ages, nor its s u b s e q u e n t rise, and the gradual steps t h r o u g h w h i c h it has r e a c h e d its p r e s e n t condition, b u t shall pass at once to a s t u d y of e n g i n e e r i n g practice as it is to-day, and shall try, b y m e a n s of a sufficient n u m b e r of examples, covering, as far as m a y be, the different kinds of e n g i n e e r i n g work of m o d e r n times, to m a k e plain what is the range and w h a t are the characteristics of the work of the e n g i n e e r to-day. P r o b a b l y the t h o u g h t of e n g i n e e r i n g in the popular mind has b e e n associated with w h a t are often called Public Works m o r e than w i t h a n y t h i n g else; and especially with the m e a n s of t r a n s p o r t a t i o n of p a s s e n g e r s and freight, and h e n c e with the m e a n s of facilitating, and, indeed, of rende r i n g possible the c o m m e r c e of the world, and also with w a t e r s u p p l y and drainage. T h e s e have often been classed as, and have often been, public works ; a l t h o u g h the fact is t h a t w o r k s which have been c a r r i e d on b y the g o v e r n m e n t at o n e time and in one c o u n t r y have been performed by p r i v a t e enterprise at a n o t h e r time and in a n o t h e r country. Moreover, at the p r e s e n t d a y the a g g r e g a t e a m o u n t .of e n g i n e e r i n g work d e m a n d e d b y p r i v a t e enterprise is much larger t h a n that required b y public works; b u t there was a time w h e n the reverse was the case, partly b e c a u s e manuf a c t u r i n g and even mining, etc., were in their infancy, and were carried on on so small a scale t h a t there was comparatively little o p p o r t u n i t y for the exercise of engineering skill, whereas, p u b l i c w o r k s were e x e c u t e d on a very extensive scale; and pgrtly because, in the case of the old monarchical and despotic g o v e r n m e n t s , it was only the g o v e r n m e n t t h a t w a s rich e n o u g h to carry out large works. F o r p r e s e n t purposes, then, we will use the following classification of public w o r k s : roads, rail-roads, bridges, canals, i m p r o v e m e n t s of rivers and of estuaries, lighthouses, w a t e r supply, drainage, irrigation. It is not m y object to e n u m e r a t e and describe the g r e a t works in these different

382

JLanzci :

[J. F. I.,

lines, b u t m e r e l y to m a k e use of a few as i l l u s t r a t i o n s of t h e c h a r a c t e r of some of t h e work of t h e engi neer. ROADS.

I o u g h t n o t to pass this s l l bj e e t b y w i t h o u t c o m m e n t , especially in vi e w of t h e f a c t t h a t so m u c h g e n e r a l i n t e r e s t is n o w b e i n g a w a k e n e d in M a s s a c h u s e t t s t o w a r d s h a v i n g b e t t e r h i g h w a y s , a nd I do n o t d o u b t t h a t t h e r e s u l t of t h e m o v e m e n t will be t h a t we shall e v e n t u a l l y secure t h e m . T h e v e r y c a us e t h a t led to t h e m o v e m e n t , and th e m o v e m e n t itself, are a d d e d e v i d e n c e s t h a t s u c h work, if it is to be p r o p e r l y done, m u s t be t a k e n in h a n d b y t h e e n g i n e e r ; and t h a t we shall n e v e r h a v e flood r o a d s as l o n g as we leave t h e de c i s i on to each m a n w h o lives, o r e a c h t o w n t h a t is s i t u a t e d on t h e road, for this m e a n s l e a v i n g i't to m e n w h o do n o t k n o w w h a t are t h e d i f f e r e n t m e t h o d s of m a k i n g roads, and w h a t are t h e r e s u l t s t h a t h a v e f o l l o w e d t h e a d o p t i o n of a n y one u n d e r c e r t a i n c o n d i t i o n s , - - t o m e n , in short, w h o do n o t k n o w t h e e x p e r i e n c e of t h e p a s t in t h a t p a r t i c u l a r line. As to t h e e n g i n e e r i n g p r o b l e m s i n v o l v e d in b u ild in g , m a i n t a i n i n g a n d rep~tiring a road, I shall onl y say a few words. In b u i l d i n g a r o a d t h e r e is a l w a y s a c e r t a i n a m o u n t of c u t t i n g a nd filling t h a t has to be d o n e ; t h e n t h e r e m a y be a v a r i e t y of e n g i n e e r i n g p r o b l e m s i n v o l v e d a c c o r d i n g to c i r c u m s t a n c e s . W e m a y h a v e to cut t u n n e l s or h a l f - t u n n e l s in t he side of a cliff, t h o u g h we t r y to avoid this w h e n we can. T h e n , if our r oa d r u n s a l 0 n g t h e side of a hill or of a m o u n t a i n , we m a y h a v e to bui l d st one walls for c o n s i d e r a b l e d i s t a n c e s to s'upport t h e road on t h e l o w e r side or to p r o t e c t it on t h e u p p e r side, a n d in t h e s e c a s e s it is a l l - i m p o r t a n t to see t h a t such walls are b u i l t p r o p e r l y , a n d h a v e a s ecur e f o u n d a t i o ~ W e m a y also h a v e t o a r r a n g e such wor ks as will c a r r y off t h e w a t e r of a n y s t r e a m s t h a t flow d o w n t h e side of t h e hill, a n d to see to it t h a t t h e s e w o r k s are able t o ' c a r r y off all t h e w a t e r t h a t will com e a t t h e t i m e of freshets, so t h a t t he r o a d m a y n o t be i n u n d a t e d . A l o n g t h e A l p i n e r o a d s we find a g r e a t m a n y t u n n e l s c u t t h r o u g h th e cliffs, and w h i l e t h e w a t e r t h a t flows d o w n t h e m o u n t a i n side of t e n passes d o w n w a r d s t h r o u g h a c h a n n e l u n d e r t h e road, it s o m e t i m e s passes o v e r t h e cliff.

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P r o b a b l y the m o s t i m p o r t a n t item to be attended to t h o r o u g h drair]age, and w h a t e v e r is necessary to secure i t should, of course, be done ; a n d the e n g i n e e r should so cons t r u c t it t h a t n e i t h e r the surface nor the subsoil shall retai~ water. T h e surface should not have a n y hollows which wi~ retain water, and should h a v e a s l i g h t pitch towards the drains. T h e e n g i n e e r m u s t t h e n d e t e r m i n e upon the kind of d r a i n s - - w h e t h e r t h e y shall be open gutters, or closed conduits, or blind drains, according to c i r c u m s t a n c e s ; but whatever t h e y are, t h e y m u s t be of sufficient capacity, and they m u s t be kept open, and not allowed to become choked u p ; he m u s t al~o d e t e r m i n e where the drains sha!l deliver the water, a n d , o f course, he m u s t build w h a t e v e r conduits are necessary. N e x t comes the c o n s t r u c t i o n of the road itself, w h e t h e r it is to be a paved street or a m a c a d a m i z e d road, and, if the first, w h a t kind of p a v i n g shall be used ; if it is to be m a c a d a m i z e d , w h e t h e r it shall have a p a v i n g beneath the m e t a l l i n g . His decision will be influenced by the nature of the subsoil, as well as o t h e r circumstances. H e has t h e n to consider the s t r e n g t h and the wearing qualities of the m a t e r i a l s t h a t , he is to use for paving o r m e t a l l i n g . T h e n also the proper b u i l d i n g of the road, i n c l u d i n g the consolidation of the m a t e r i a l by means of the road roller. T h e n come the questions of w h a t a r e t h e repairs t h a t m u s t be m a d e in order to m a i n t a i n the road in good condition. A g r e a t m a n y other matters are liable to require a t t e n t i o n , as the curbstones, the catchbasins, the sidewalks, etc. T h e e n g i n e e r m a y have to erect road bridges, a n d these, of course, involve all the usual problems of d e s i g n i n g and erecting bridges, including the proper f o u n d a t i o n s , etc., b u t I shall not stop to discuss these at present. As to the a m o u n t of m a c h i n e r y t h a t will be required, this depends upon the n a t u r e of the road. In some cases b u t little is needed, and in o t h e r cases a very considerable amount. RAILROADS.

L e t us consider n e x t the e n g i n e e r i n g work required on our railroads, of w h i c h there are a b o u t I7O,OOO miles in the

384

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[ I. F. I.,

U n i t e d States, and w h i c h exert so large an influence u p o n t h e comfort and h a p p i n e s s of all the i n h a b i t a n t s of o u r country. I shall not w e a r y y o u w i t h the story of G e o r g e Stephenson's efforts, trials and t r i u m p h s w h e n he b u i l t the f a m o u s R o c k e t for the Liverpool and M a n c h e s t e r R a i l r o a d in 1829, a story with which e v e r y s c h o o l b o y is familiar, b u t shall proceed to a consideration of w h a t is some of the engineering work t h a t has to be done in b u i l d i n g , in e q u i p p i n g and in r u n n i n g a railroad. W e m a y a d o p t the following as a c o n v e n i e n t classification of the diYferent d e p a r t m e n t s t h a t involve e n g i n e e r i n g operations, viz.: (i) p e r m a n e n t w a y ; (2) rolling stock; (3) stat i o n s ; (4) signals; (5) bridges. P e r m a n e n t /4Zay.--Beginning w i t h the p e r m a n e n t way, there is first the location of the road, and this involves a v e r y large n u m b e r of q u e s t i o n s t h a t require careful judgm e n t for their solution; of course, it is n e c e s s a r y to take into account primarily t h e a m o u n t of traffic that can be s e c u r e d b y any p r o p o s e d r o u t e ; at t h e s a m e time due r e g a r d m u s t be h a d to t h e expenses t h a t will h a v e to be incurred, b o t h for first cost and also for o p e r a t i n g the line; this, of course, i n t r o d u c e s a consideration of the g r a d e s t h a t will h a v e to b e s u r m o u n t e d , the c u r v e s t h a t will h a v e to b e tolerated, the b r i d g e s t h a t will have to be built, t h e excavations t h a t will have to be made, the difficulties t h a t are liable to p r e s e n t t h e m s e l v e s in k e e p i a g the road in repair, s o m e t i m e s the difficulties to be m e t w i t h to keep it clear of snow, and a host of o t h e r considerations ; t h e n the actual work to be done in m a k i n g t h e surveys, and fixing t h e location in a n e w c o u n t r y m a y involve a good deal of work, and a r a t h e r r o u g h - a n d - t u m b l e life. In America, i n s t e a d of b u i l d i n g the road up to the s t a n d a r d we should desire at t h e start, it is m u c h m o r e c u s t o m a r y to b u i l d it poorly at first, and then m a k e i m p r o v e m e n t s as fast as m o n e y is earned w i t h w h i c h to m a k e them. So, in the first b u i l d i n g of the road, the e n g i n e e r may, to save expense, allow steeper grades and s h a r p e r curves than w o u l d p e r h a p s b e n e c e s s a r y if a little more e x p e n s e were incurred, w i t h t h e idea that

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En~ineering Practice and l~clucation.

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after the line has been in operation for a while, and has earned a sufficient a m o u n t of m o n e y to w a r r a n t it, the curves can be s t r a i g h t e n e d out a n d the g r a d e s r e d u c e d ; but he m u s t see b e f o r e h a n d how this can be done. L e a v i n g to one side for the present the m a t t e r of the bridges, we will a s s u m e t h a t the road is located, a n d t h e p e r m a n e n t w a y is to be built. W e have now, to a certain extent, a set of ques. tions similar ~o those t h a t arise in the ease of common roads. T h e r e will be, of course, a g r e a t deal of c u t t i n g and filling. For t a k i n g out h e a v y c u t t i n g s we use s t e a m shovels, one of which can d o the work of 50o men, and w h e n the e m b a n k m e n t is m a d e from e a r t h t h r o w n up from ditches on each side, d i t c h i n g m a c h i n e s are used, some of which can t h r o w up 3,ooo cubic y a r d s per day. In this case, j u s t as in the case of a c o m m o n road, we m u s t see to it t h a t the roadbed is t h o r o u g h l y drained, and now, after the roadbed is made, we m u s t p u t on a good layer of ballast of broken stone. This is t h e best, for it does not hold moisture. Moreover, t h a t the ballast s h o u l d be h a r d and well packed and should not hold moisture, are considerations of prime importance. On top of this ballast are placed the sleepers, which are carefully laid at the proper distance apart, and are so a d j u s t e d as to h a v e an even b e a r i n g on the ballast ; t h e n their upper surfaces are dressed and the rails are laid down ; t h e n the roadbed is covered w i t h gravel, which should be up to the tops of the sleepers, and t h e n the chairs are placed and the rails are spiked down. T h e n the u p p e r ballast or gravel is t a m p e d in u n d e r the sleepers so as to cause t h e m to have so t h o r o u g h a b e a r i n g t h a t t h e y will receive the pressure of the rail equally. Now, besides the bridges on the road, there are a good m a n y culverts, or small bridges t h a t have to be built, w h e r e w a t e r drains off, a n d for o t h e r reasons. W h e n they are to be p e r m a n e n t t h e y are u s u a l l y b u i l t of stone, b u t very often t e m p o r a r y ones are built of trestle work, and this is often s u p p o r t e d on piles. Hence, we have use, so far, for $team shovels, d i t c h i n g machines, pile drivers, and sometimes s t e a m dredgers. Next, as to the rails; their w e i g h t h a s g r a d u a l l y increased from thirty-five p o u n d s in the days o f George Stephenson, to e i g h t y , n i n e t y and even IOO pounds Vow.. CXXXVII 25

386

Lanza :

[J. F. I.,

per y a r d at the present day. Moreover, while the first rails u s e d were of wood, t h o s e of George S t e p h e n s o n were of w r o u g h t iron, b u t now t h e y are a l m o s t exclusively m a d e of Bessemer or open-hearth steel; a n d this increase in the w e i g h t and the s t r e n g t h of the rails has been b r o u g h t a b o u t of necessity in consequence of t h e increase in the w e i g h t s of the locomotives from five or six tons for e n g i n e s like the R o c k e t to fifty tons a n d more to-day. A n o t h e r m a t t e r which the b u i l d e r of a road in a settled c o u n t r y is liable to have to consider is the works n e e d e d to avoid grade crossings. T h e n in r e g a r d to tunnels, the A m e r i c a n locomotive is so constructed t h a t it can go a r o u n d m u c h s h a r p e r curves t h a n the E n ~ i s h or the E u r o p e a n locomotive, and hence we can avoid t u n n e l s m u c h more easily t h a n we o t h e r w i s e could. A f t e r the p e r m a n e n t w a y is e s t a b l i s h e d it requires cons t a n t and careful a t t e n t i o n , as a v a r i e t y of u n f o r e s e e n accidents are liable to happen. W a s h o u t s m a y carry off bridges or culverts, w o o d e n trestles m a y rot or take fire, rails m a y break, chairs m a y break or g e t loose, spikes m a y come out, landslides m a y occur in m o u n t a i n o u s regior~s, o b s t r u c t i o n s m a y g e t on the track, collisions or accidents m a y occur. All these t h i n g s m u s t be g u a r d e d a g a i n s t by a m o s t careful inspection, and w h e n a n y t h i n g is f o u n d out of order, it should be repaired at once. T h e n a n o t h e r m a t t e r t h a t devolves on t h e inspection and repair g a n g is t h e following, viz.: t h e road, a n d h e n c e the rail, is liable, t h r o u g h u n e q u a l s e t t l e m e n t , to acquire an u n e v e n u p p e r surface, this occurring m o s t f r e q u e n t l y at the joints, and t h e n not only is the r i d i n g m a d e u n c o m f o r t a b l e , b u t also there is more power r e q u i r e d to draw the t r a i n t h a n would be the case if the surface were even. Hence, it is a m a t t e r of importance, from the point of view of economy, to keep the r o a d b e d in first-class condition. Some roads h a v e a d y n a m o m e t e r car which is p r i m a r i l y a car c o n t a i n i n g m e c h a n i s m by w h i c h we can o b t a i n a record of the pull on the draw-bar at a n y g i v e n i n s t a n t , or for a n y given position of the train on t h e road. T h e s e cars are u s u a l l y provided w i t h a n o t h e r m e c h a n i s m , which, whenever the car passes a hollow in t h e track, t h r o w s a little

May, I894.]

Engineerilzg Practice and Education.

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paint on the side of the rail near the place. W h e n a road has one of these d y n a m o m e t e r cars it generally uses it for t h i s purpose, and then the t r a c k m e n find the paint and proeeed to level up the track at that place. If it does not have a d y n a m o m e t e r car of its own, it often hires, s o m e one who has, to make t h e inspection. All t h e s e things require a large force to keep the p e r m a n e n t w a y in order, and it needs to be i n s p e c t e d c o n s t a n t l y in all its parts. W h e n , however, there is a break-down, it is often easier to b r i n g men and fiaaterial from some distant central d e p o t than to try to g e t along with such appliances as can be f o u n d near by. It m a y be .well to say t h a t on our railroads there have been, and are still to be found, a large n u m b e r of t i m b e r bridges, and that, doubtless, in the earlier days of the country, it w o u l d not have been possible for the roads to afford t h e m o n e y to b u i l d iron b r i d g e s ; b u t that n o w steel bridges are the rule, and while t i m b e r is still used for temporary work, its use for p e r m a n e n t work in the w a y of railroad b r i d g e s is fast d y i n g out. Rolling Stock.--We next come to the rolling stock. As soon as the road b e c o m e s of considerable m a g n i t u d e , the works connected with it have to be v e r y extensive, and require a large a m o u n t of e n g i n e e r i n g work. One m i g h t i m a g i n e that w h e n once the rolling stock is all purchased, if the road is small and not growing, and if the shops and buildings for the h o u s i n g and the repair of the rolling stock are all built and e q u i p p e d and in operation, that the looking after e v e r y t h i n g to keep it in proper order and repair, and the p u r c h a s i n g of the supplies needed, as coal, oil, etc., while it w o u l d involve the exercise of c o n s i d e r a b l e executive ability, need not involve any considerable a m o u n t of e n g i n e e r i n g w o r k ; b u t as a n y one w h o carries on s u c h 'work k n o w s v e r y well, the m a n a g e m e n t of a business w h e r e so large an a m o u n t of m a c h i n e r y is concerned, necessarily involves a large n u m b e r of e n g i n e e r i n g problems. As examples, shops have to be enlarged or new ones built ; new and i m p r o v e d or m o r e p o w e r f u l m a c h i n e r y has to b e introduced, which m a y involve v a r i o u s r e a r r a n g e m e n t s ; alterations in s o m e of the d e t a i l s of the r u n n i n g gear or

388

Zanza :

[J. F. I.,

of some other portions of locomotives or e a r s ; t h e prov i d i n g of additional space for r e c e i v i n g coal, a n d of suitable a r r a n g e m e n t s a n d facilities for d e l i v e r i n g it w h e r e n e e d e d ; m a k i n g s u i t a b l e a r r a n g e m e n t s for k e e p i n g cars at such places as are n e e d e d on the road, so as to h a v e t h e m r e a d y when and where t h e y are n e e d e d ; t h e e s t a b l i s h i n g the necessary y a r d s w i t h the proper tracks and s w i t c h e s ; establishing the necessary s t a t i o n a r y boilers, pipes, etc., to h e a t the cars before s t a r t i n g ; t h e n comes the care of a n d the runn i n g of the shops, for a n y railroad, no m a t t e r how small, m u s t h a v e at least a repair shop, and, as in such a repair shop, the road mu~t be p r e p a r e d to m a k e anew a considerable n u m b e r of t h e parts of the locomotives a n d cars, the question always arises h o w far to go in m a n u f a c t u r i n g the parts new, and t h e n how far to go in t h e m a t t e r of building, in whole or in part, new locomotives, a n d h e n c e will arise all degrees of d e v e l o p m e n t in this regard, u p to the point where the road m a n u f a c t u r e s all its own rolling stock, involving, in t h a t case, a very large a m o u n t of e n g i n e e r i n g work. A n o t h e r m a t t e r t h a t be6omes of i m p o r t a n c e , as soon as t h e road is able to afford such a d e p a r t m e n t , is a departm e n t of tests. T h i s d e p a r t m e n t u s u a l l y has c h a r g e of tests of all kinds, including, of course, tests of oils a n d tests of t h e s t r e n g t h of materials, and a n y o t h e r tests w h i c h it m a y be d e e m e d best for the road to make. T h u s , suppose t h a t the road is c o n s i d e r i n g t h e advisa b i l i t y of a d o p t i n g some new k i n d of l o c o m o t i v e for a cert a i n kind of service, a n d desires to know w h e t h e r t h e change is liable to result in economy, especially in s a v i n g coal or not, it m a y be wise to have a series of c o m p a r a t i v e or even of absohlte tests m a d e to d e t e r m i n e e i t h e r its relative or its a c t u a l p e r f o r m a n c e in r e g a r d to coal and w a t e r consump-' tion. Or suppose t h e road is c o n s i d e r i n g the advisability of m a k i n g some c h a n g e in the details of its locomotives or cars, and wishes to determine" t h e effect of the change, as, for instance, in t h e brake gear, or in t h e m a n n e r of h e a t i n g t h e cars, or in some a r r a n g e m e n t for v e n t i l a t i n g t h e m , all such m a t t e r s w o u l d come to the test d e p a r t m e n t ; besides

May, E894.I

En~ineering Practice and EducatioJz.

389

which, if the road is large, t h e r e will be e n o u g h chemical tests to keep at least one c h e m i s t busy, as tests of oils, of paints and varnishes, chemical tests of the m a t e r i a l s used, etc. Then, of course, if n e w shops are to be built and equipped, there arises a v a r i e t y of problems, first in r e g a r d to the f o u n d a t i o n s of the buildings, t h e n as to the details of the buildings, their proper strength, heating, ventilation, light and a d a p t a b i l i t y to their purpose ; their a r r a n g e m e n t so as to require as little h a n d l i n g of the m a t e r i a l as possible ; the choice of the m a c h i n e r y to be used ; its arrangem e n t ; w h e t h e r t h e r e shall be m u c h special m a c h i n e r y , and if so, w h a t ; the power plant; w h a t kind of engines will be best to use u n d e r the c i r c u m s t a n c e s of the case; how m a n y t h e r e shall be, and w h e r e located ; the l a y i n g out of the entire s y s t e m of driving, including shafts, pulleys and belting or o t h e r modes of driving, if t h e y are to be u s e d ; the steam boilers to be used; the erection of a suitable boiler house and c h i m n e y and its location ; ' t h e f o u n d r y ; the forge shop and its e q u i p m e n t , possibly i n c l u d i n g h e a v y steam h a m m e r s ; the boile~ shop, with all the n e c e s s a r y machinery, as plate-shearing, b e n d i n g and planing machines, p u n c h i n g and drilling machines, hydraulic, s t e a m or compressed air riveters, etc., besides the n e c e s s a r y cranes, etc., for h a n d l i n g the boilers in process of construction, as well as the establishing of suitable cranes or trolleys for handling the materials in all the shops in the best and easiest m a n n e r ; the c a r p e n t e r shop ; the e r e c t i n g shop for the locomotives. In the case of a n u m b e r of large locomotive works, cranes are provided which can lift the entire locomo. tive and carry it from one part of the shop to another. T h e n t h e r e is the b u i l d i n g of the transfer tables, the building of the ears, with all the necessary appliances of brake pipes, h e a t i n g pipes, lamps, couplers, seats, etc., the painting and v a r n i s h i n g of the cars and u p h o l s t e r i n g them, etc. Then, in the case of v e r y large railroad shops, the road might decide to m a k e and roll its own steel, w h i c h would, of course, involve a complete f u r n a c e plant and rolling mill.

390

Lanza :

[J. F. I.,

T h i s course is followed b y the L o n d o n and N o r t h w e s t e r n R a i l r o a d at Crewe, E n g l a n d , w h e r e t h e y h a v e a Bessemer p l a n t with .four converters, each of w h i c h is capable of t u r n i n g out five tons of steel at one heat. T h e pig iron, w h i c h t h e y b u y elsewhere, is m e l t e d in a cupola furnace, and the m e l t e d m e t a l is t h e n carried by m e a n s of large ladles to the converters, w h i c h are vessels t h a t can be t u r n e d over on t h e i r sides and back to an erect position, as t h e y are m o u n t e d on t r u n n i o n s . T h e c e n v e r t e r is t u r n e d on its side, a n d t h e m e l t e d pig iron is p o u r e d from the ladle into t h e converter. T h e n a p o w e r f u l b l a s t is introduced, and t h e converter is t u r n e d back to an u p r i g h t position, w h e n c o m b u s t i o n goes on violently, the o x y g e n of the air b u r n i n g o u t t h e carbon of the pig iron. W h e n this c o m b u s t i o n has gone on for a s u i t a b l e l e n g t h of time, u s u a l l y fifteen or t w e n t y m i n u t e s , a d e t e r m i n e d a m o u n t of spiegeleisen, i. e., an iron rich in carbon and in m a n g a n e s e , is m i x e d w i t h t h e m e l t e d mass ; t h e n t h e conv e r t e r is t u r n e d on its t r u n n i o n s , a n d , t h e l i q u i d steel is p o u r e d into a ladle, w h e n c e i't is r u n into t h e cast-iron i n g o t moulds, a n d is t h u s f o r m e d into ingots. T h e y also h a v e an open h e a r t h plant, w i t h seven SiemensM a r t i n furnaces, £ e., five twenty-ton, and two ten-ton furnaces. T h e s e are,. of course, r e g e n e r a t i v e f u r n a c e s w h e r e the gas is m a d e in gas producers s i t u a t e d elsewhere, and is b r o u g h t to the f u r n a c e s t h r o u g h pipes laid u n d e r t h e ground. T h e n t h e gas on its p a s s a g e to the f u r n a c e passes t h r o u g h a red-hot checkerwork of firebrick, while the blast is i n t r o d u c e d a f t e r p a s s i n g t h r o u g h a n o t h e r red-hot checkerwork; the comb u s t i o n takes p!ace in the furnace, w h e r e are placed t h e pig, t h e scrap, and o t h e r m a t e r i a l s r e q u i r e d ; and then, as the air a n d g a s m e e t at a h i g h t e m p e r a t u r e , c o m b u s t i o n occurs and t h e carbon is b u r n t o u t of the m e l t e d m a s s ; t h e n the hot gases pass out t h r o u g h two o t h e r - e h e c k e r w o r k c h a m b e r s to t h e c h i m n e y , t h u s h e a t i n g up the~se chambers, so t h a t the gas and air can be m a d e to e n t e r t h r o u g h t h e m w h e n the o t h e r two h a v e become too cool: T h e y h.ave a rail-making p l a n t of 45,ooo tons a n n u a l capacity, a n d also a mill for m a k i n g tires for locomotives and car wheels ; a mill for mak-

May, I894.]

Engineering Practice and Education.

39 x

i n g plates, and a mill for m a k i n g m e r c h a n t bars and other shapes w h i c h t h e y m a y require. T h e s t e e l f r o m these rolling mills is t h e n carried to the o t h e r shops, where it is to be used, on ears d r a w n by a small locomotive on a narrow g a u g e railroad which goes to all parts of the works. I t m a y be well to say a little more a b o u t these e n o r m o u s works at Crewe, where the L o n d o n a n d N o r t h w e s t e r n Railroad can s t a r t from the raw m a t e r i a l a n d make all parts of its locomotives and o t h e r machinery, except copper plates and brass t u b e s . T h e s e works not only m a k e locomotives, b u t also all the s i g n a l l i n g apparatus, and the signal cabins themselves, also cranes and o t h e r m a c h i n e r y , and even bricks, drain pipes, and also gas, besides w h i c h t h e y have t h e i r own w a t e r works. T h e total area enclosed by the works is one h u n d r e d and sixteen acres, whereas the buildings cover thirty-six acres. Of course, the shops where the locomotives are manufact u r e d and repaired contain an e n o r m o u s a m o u n t of machinery, and a m o n g the rest a considerable a m o u n t of special m a c h i n e r y . T h e steel p l a n t is capable of t u r n i n g out 5,ooo tons of s~eel a year, and the total n u m b e r of locomotives t h a t h a v e been m a d e there up to May, I89O, was 3,I35. T h e g r e a t e r portion of the parts of the locomotives of a given class which t h e y build t h e r e are i n t e r c h a n g e a b l e , b e i n g m a d e to s t a n d a r d sizes; so t h a t if in an accident almost a n y one part of an e n g i n e is broken, a n o t h e r can be f o u n d in stock which will be s u i t a b l e to put in its place and which will fit at once. T h e r e are about6,5oo men e m p l o y e d at these works, where a b o u t ~,ooo e n g i n e s a year are repaired, and where as m a n y as I46 h a v e been m a d e in one year. To establish and keep up this e n o r m o u s place it has been necessary for the road to m a k e provision for e n a b l i n g its w o r k m e n to live there, as the t o w n h a s practically been b u i l t up b y the railroad. T h e c o m p a n y own a b o u t 850 houses, and t h e y h a v e b u i l t at t h e i r own expense a Mechanics' I n s t i t u t e and a church, and t h e y have done a great deal to f u r n i s h to t h e i r employ6s and t h e i r families opportunities for i m p r o v e m e n t and a m u s e m e n t . T h e cars are not m a d e at Crewe, b u t at Wolverton, where

392

Lanza :

[J. F. I.,

the works cover about fifty acres, and where t h e y employ 2,200 workmen, and where they b u y the wood in the form of logs, and again they have a narrow gauge railroad running to all parts of the works, and cranes of all sorts, so as to be able to handle the material and the work easily. The timber is sawed into planks or w h a t e v e r form may / be desired here, and then it is put into a drying room and seasoned, before it is used in building cars. T h e wheels are also made at Wotverton, these being wood wheels with steel tires, the wood being forced into the tires by hydraulic machinery. Then, of course, there is done here all the upholsteriffg, painting, varnishing, etc. W h e n we consider the extent and magnitude of these works, it is evident that there is the necessity fo; a very large amount of purely engineering work. T h e p u t t i n g up of the buildings alone involves questions of adaptation of the arrangement to the greatest economy in handling, consistent with efficient working; adaptation of the form and proportions to the work to be done in them i questions of suitable foundations; questions of light ; questions of strength of materials, especially considering the heavy loads that have to be borne in some of them ; questions of chimney power, and of foundations for and stability of chimneys, of draught of chimneys, etc. T h e n besides this the road has to do all the engineering work for a large town and has to make provisions for a great deal that usually belongs to the town to provide, and not to a railroad corporation, thus it has to supply the town with water and gas, and all this means water works and gas works, and the solution of engineering problems that arise in connection with them. T h e n it has not only to build its own shops b u t also houses in the town, hence it has to make b r i c k T h e n in order to mak~ all the saving possible in labor, there is required a l a r g e amount of special machinery, and to design such, a man needs to be familiar with mechanism, and with the design of machinery, including questions as to its strength, its stiffness, and its proportions generally, as for instance, its bearing surfaces, etc. T h e n need I say that the steam plant needs attention ?

May, I894.]

Enffineerinff tJractice and Education.

393

A r e the engines and boilers, and their a r r a n g e m e n t and r u n n i n g such as Will ensure t h e g r e a t e s t e c o n o m y ? Also the a m o u n t of coal and iron and o t h e r materials b r o u g h t into these works m u s t be s o m e t h i n g enormous, hence means m u s t be p r o v i d e d for r e c e i v i n g them, for u n l o a d i n g them, and for s t o r i n g t h e m until t h e y are needed. Then, b e s i d e s all these q u e s t i o n s w h i c h involve a knowledge of mechanism, of s t r e n g t h of materials, and of steam engineering, etc., we have u s e for electricity in various ways. T h e first t o p r e s e n t itself to one's m i n d in connection w i t h a railroad will n a t u r a l l y be the signalling; b u t there are also other connections in which, if it is not m u c h used yet, I do not d o u b t it will be ere long, viz : electric lighting, not only for t h e shops, b u t also for the cars, for a l t h o u g h electric l i g h t i n g of s t e a m cars has not t h u s far prog r e s s e d to the p o i n t w h e r e it is at all rivalling or likely to rival for some time the m e t h o d s of l i g h t i n g b y gas or b y oil; nevertheless, I believe t h a t in course of time more progress will be m a d e in this direction, and then we shall come to h a v e our s t e a m cars lighted b y electricity; also in the use of electric brakes, which at p r e s e n t are e m p l o y e d only to a small e x t e n t ; also in the use of electric cranes, which are the m o d e r n form of crane w i t h o u t any question. Indeed, electricity is g r a d u a l l y displacing o t h e r m e t h o d s of driving cranes in o~r large shops and rolling mills and bridge works. By using it w e avoid a g r e a t m a n y c l u m s y m e t h o d s of t r a n s m i t t i n g power, for t h e p o w e r has to be applied in such a w a y t h a t the crane can be driven w h e r e v e r it stands in its travel. A n electric m o t o r carried b y the crane itself, with the c o n n e c t i n g wires, furnishes an easy and neat m e t h o d of transmission, and does not involve so m u c h loss b y friction. T h e application of electric motors to cranes will, in m y opinion, be extended to a large e x t e n t to o t h e r m a c h i n e r y in our large m a c h i n e shops and manufactories, and I b e l i e v e it will not be m a n y y e a r s before electric transmission of p o w e r will displace a g r e a t deal of the s h a f t i n g and b e l t i n g w i t h w h i c h o u r shops are so m u c h filled up at present. Besides all this we h a v e o p p o r t u n i t i e s and the n e c e s s i t y

394

Chemical Section.

[ J. F. I.,

for a large amount of engineering knowledge and engineering work in the design and construction of the locomotive itself. W h a t are the conditions which we wish our locomotives to fulfill? T h e y are to draw our trains at as high a speed as is consistent with safety, and to do this with the least expenditure for coal, for water, for repairs, etc., Mso to fulfill all the special conditions of the particular service which they are to perform, such as going around sharp curves, going up steep grades, hauling heavy trains, etc. Of course, it is necessary that they should have the requisite strength and stiffness. Now, we have here at once questions of mechanism, questions of strength of materials, and questions of steam engine economy. [ To be continued.]

N O T E ON P E M B E R T O N ' S M E T H O D OF P H O S P H O R I C ACID D E T E R M I N A T I O N AS C O M P A R E D WITH THE O F F I C I A L METHODS.* BY WM. C. DAY AND A. P. BRYANT.

Having oceasion to make a series of d e t e r m i n a t i o n s of phosphoric acid in Florida phosphate rock, we have used the method recently described by Mr. H. Pemberton, Jr.,t and incidentally have made a n u m b e r of comparisons between it and the official method. The following are the results : GRAVlM~TRIC DETeRMINATIOnS.

No. NO. No. No. No. No.

I. I. 3. 33. 4.

F r o m 0"7867 grins. N a 2 H P O 4 + I2H20, obtained 0"2426 grms. Mg~P20~ F r o m I'IIOOgl~ls. N a z H P O , ~- I2H20, obtainedo'3433 grins. MgaP,O~ P r o m i'oooo grams Florida rock, obtained o'5828 grams Mg2P20~ F r o m 0"3807 g r a m s Florida rock, obtained o'o262 grams M g 2 P 2 0 ~ F r o m o'483I g r a m s Florida rock, obtained o'o333 grams M g , P , O ~ F r o m I'oo36 g r a m s Florida rock, obtained 0"0527 grams M g 2 P , O v

* Read at t h e stated m e e t i n g of t h e Chemical Section, held F e b r u a r y 20, x894. t Jour. Frank. Inst., 1 3 6 , 362.