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Water wheels
AMERICAN MECHANICS~ ~[AGAZINE,
103
of a~rial currents, hydrometrical observations may be made with great accuracy. In lieu of having points attached to the chyometer, as represented_in the figure, it may be as convenient to have two small holes9 for the insertion of the points of a pair of compasses, either of the common kind, of the construction used by clock makers, or that which is known under the name of beam compasses. The compasses may be used to regulate the opening of the sector, or to ascertaln~ by the aid of that instrun~ent, the comparative value of the distances which the rod of the chyometer has to be introduced into its tube. In order to convey an idea of the nature of the sector to any reader who may be unacquainted with it, I trust it will be sufficient to point out, that its construction is similar to that of the foot-rule used by carpenters. We have only to suppose such a rule, covered with brass~ and each leg graduated into 200 equal parts, in order to have an adequate conception of the instrument employed by me. A more particular explanation of the principle of the sector, may be found in any Encyclopedia, or Dictionary of Mathematics.
WATER WHEELS. On t h e construction o f water wheels a n d tile m e t h o d of applying t h e water for propelling them so as to produce t h e greatest effect.
7'0 the Committee of the Franklin Institute b~ PMladelphia. In constructing water-wheels, especially those of great power, the introduction of iron is a most essential improvement, and if this metal, and artisans skilled in tile working it, could be obtained at reasonable rates, water wheels might be made wholly of it, and prove ultimately, the cheapest, as if mana~edv with due care, .and worked with pure (not salt) water, they would last for centuries ; but as the first cost would 6e an objectlon~ I would recommend ia all very large wheels that the axis be made of cast iron, and in order to obtain the greatest strength with the least weight, the axis or shaft ought to be cast hollow, and in the hexagon or octagon form, with a strong iron flange to fix each set of arms and the cog wheel upon ; these flanges to be firmly fixed in their places with steel keys. On the adaptation of water wheels to the different heights of the water falls by which they are to be worked, I remark that falls of 9. to 9 feet are most advantageously worked with tile undershot wheel ; fall,s of 10 feet and upwards by tile bucket or breast wheel, which up to 20 or ~5 feet ought to be made about one-sixth higher than the fall of water by which it has to be worked ; and in wheels of both descriptions, the water ougl~t to flow on the wheel fi'om the
10']:
THE FR,'LNKLIN JOUft~NAL AND
surface of the dam. I am aware that this principle is at dh'ec~. variance with tim established pcactice, and perhaps there are few wheels in these states that can be worked as they are now fixed~ by thus applying the w a t e r ; the reasons will be apparent frora what lbllows. In adjusting the proportions of the internal wheels by whicl~ machinery is propelled, it is necessary, in order to obtain the greatest power, to limit the speed of the skirt of tim water wheel, so that it shall not be more than from 4 to 5 feet per second ; it havin~, been ascertained by accurate experiments, that the greatest fl~rce of water obtainable, is within these limits. As a falli~lg body, water descends at the speed of nearly 16 feet in the firs~ secoml, and it willappear evident that if a water wheel is required to be so driven, that the water with which it is loa,led has to descend 10, 11, or 19. feet per second, at which rates wheels are generai!y coust,-ucted to work, that a very large proportion of'the power is lost, or rather, is spent, in destroying, by unnecessary friction, the wht:el it is flowing upon. lu the common way of constructing mill work and of applying water to wheels, it has been found indispensably necessary to have a head of from ~ to 4 feet above the aperture through which the water ttows into the buckets, or against the floats of a water wheel, in order to be able to load the wheel instantaneously, anti without which precaution it could not be driven at the required speed ; from this circumstance it has been erroneously inferred that the impulse or shock which a water wheel so filled receives, is greater than the power to be derived fl-om the actual gravity of the water alone. This theory I have heard maintained among practical men, but it is, in ['act, only resorting to one error to rectify another. Overshot whei~ls have been adopted in numerous cases merely for the purpose of getting the water more readily into the b u c k e t s - - b u t con° tine the wheel to the proper working speed~ and that difficulty does not exist. In conseq~lence of the excessive speed at which water wheels are generally (h-iven, a small aecumulaticn of backwater either suspends or materially retards their operations, but by. properl,y confilfi~g their speed, the resistance from back water is cons~derably diminished and only amounts to about the same thing as worki~lg"from a dam as many inches lower as the wheel is immersed ; nnd in undershot wheels worked from a low head, or situated ir~ the tide-way, the resistance from back water may be farther obviated by placing the floats not exactly in a line from the centre of the wheel, but deviating 6 or 8 inches from it, so as to favour the water leaving the float ascending. In constructing water wheels to be driven at the speed of 4 to 5 feet per second, it will be requisite to make them broader to work the same quantity of water which is required to drive a quick speeded wheel. Thus if a person intending to erect a mill, has a stream sufi~icient to work a wheel 5 feet broad, the s k i r t to move ]0 feet per second, it is evident that if he wishes to work all th~
AMERICi~ ~,mct~Amcs* ,szat~AZt.~E. . . .
TO'~
water which such wheel takes, he must have his wheel 10 o r 12 feet broad, instead of 5, otherwise tile water must run to waste, as there would not be room in a slow moving wheel of 5 f e e t broad to receive more than half of it. 'File i;rineipal advantages resulting fi'om the prtq3osed method of adapting wheels to the falls by" which thoy are to be worked, and the method ofapplyiug water~ are : 1. The lessenin~ of triction upon the main gudgeons~ (and first pair of cog wheels,) t~y which, with a little care, they may be kept regularly cool, and the shaft or axis be preserved n{uch "longer in use than wl~en the gudgeons cannot be kept cool. • £ . By working water upon the principle of its actual gravity alone, aud applp.ing it ahvavs at the height of the surface of the dam, its power is d'ouble w~at is obtained by the common method of applyiu~ it. •% The exl~C;aslve penstock reqt~]ved ~,n convey the waler to tile w h c ( ' ] 5 , ~gCt!Cl'D.lly u s e d , x, I[~ li:tt b e lieCd(.,t! r i~+ {)Ii~.: illlich s]l;.tllt)*e,'el'?
and consequuntly less expr.~:~;ve, will be. ~ufftcient. 4. The resistance of back wa!er is reduced as fat" as possible. 5. The risk of Ih'e is less, as lhe lric~i,m is re-lueed. ] shall clo~e lhis paper with remarks upou th.'s~ e~tablishments I have inspected in the course of the presenl year. Mr. S m i t l e s n e w l y e v e c l t ' d corn mill tm lhe Rarito:a, at New.Rruuswick, N. J., has wa~or wheels 1~.; feet lfigh and 14 feet b l , a d , wifich ave worked l r. ( a hold . f f , ur feet. 'l'h~:~ater ~ t~eels lu,lke. 1~ rev ,lull( ~ ~ pet" tr, h!nlc, equal t(~ l0 feet lWl• second, when tile stones (five feet diamt, tev) make 100 |'evoh|tious. The water wheels at the flour mills at Braudywine, near W i l min~ttm, ave worked at the speed of 10 to 15 revolutions per mhlut% the Wheels ge,,leralty 16 feet hi/~h, and the fall 9.0 feet. iu all these establishment% Uaere is not obtained 30 pet" cent. of the Vtwer of the water used. 'l'he wa~er v¢l'~e~qsat F a i r Mount, used for supplying Philadelp]~i,~ with v,ater~ are 16 feet high anti 14 feet wide, worked by a head CA 5 feet; lhey are driven at tile ra~e of 15 revolutions i~er minute, which is equivalent to 11 feet per second for t h e ' m o t i o n of the skirt of the wheel. The machinery used here, is highly creditable to the workmen who put it up; but if the principle of applying water, which I have endeavoured to establish, be correct, it will be readily perceived, ~hat a very considerable loss of power is sustained by its mode.of applieafic~t. If these water wheels, as situated at present, were confined t~ mc-ke no more than 5 revolutitms per minute, and lhe pumps to lnake (lie same number of strokes that they now do, that is I 5 double strokes, tile water flowing agait~st (tie'wheel at the surface of lt~e dam ; each wheel would work two of the l:,umps, ~xill~ the watc.r that is r, ow taken to work one. But if the wt~eels were l)laccd I inches lower in the tide-way, two-thirds of the watery required 1~ work tree pump, would work two at equal speed, whih. the xxiwel continued free, and it would require no Iliore ihan i~ ut)\v ~scd t,~ "~'OL. [ , ~ . ~ O .
0 ,__L'I-|,,:V~I,i," ][t,>¢
I ~t
106
"r~g .~fLAN'KLINJOUR~.~L AND
work one pump, to work two with the wheel immersed 18 inches in the ~ide. This will. I trush be sufficiently clear, when it is consi,Jered, that by the reduced speed~ an addition of 150 per cent. in the quantity of water is thrown into the wheel and kept there, to~,~ed,er with the advantage gained between the water descending tour and ot~e-oighth ittstead of 11 feet per seco~d. Sel~lentber ~4, 18'25. W. P/tiC.KIN, Engineer,
STEAM E N G I N E S . The ~ubjoined account of the steam engines in use in Glasgow and it~ viciuity, at the. beginning ,)f the year 1825, exhibits a ereatio~ of physical force, applied to the p]~rposes of manufacturing, within the short space of thirty-three y~'ars, which is well worthy the notice of the cilv of Phila~felphia. The population of the two cities is nez~rlv equal, and the conviction is general, that we are well ~ituated f)w the business of manufacturing, and that our prosperity is intimately cotJnected with its establishment. Besides ~ho~e mat;~l'ac~ures extensively carried on in Glasgow~ there is one of vast importance, and which it is in our power extensively to pr,.,secute ; the manufacture of broad-ch)th and other fabrics of wool, eilher alt)ne or in mixture. Enough has been done in the United States, to prove that in nearly every department of that I)usincss~ blbour-saving machinery may be employed, with advantages ¢'qual to those exhibited in the manufacture of cotton. It is the detcr~z~iuali(m of the Editor to present'this subject more fully~ in a~l early I u btr d'this journal, as the views which it opens are t~-) mlmero~l~ and too important, to be dismissed in the compass of ,~ few l i r ~ e s .
'l'hc C~Wl>~)rat~onof ~be city would, it is believed, pursue a policy a~ wi~e as it ~voabl I)e libcr;~f, were they fi)r a limited time, to allow i~c fwc u,~e ~)f t!,~e Schuylkill water, for the supply of all the steam ~;~;,dm,~+, wl,.ich sh+~:;Id be built~ and applied to manufacturing purp,,-~'~, witi~i~ a c~,~'t,i~ period. This might be done without any iw('s~r~t loss ; v,l~ilst it w,,uld tend to give that activity to industry, ~,~hle to pr~q~erty, aml e~l)lo)ment to capital, which would immedi,~t~qy, alt!,~t~h it~directly~ more than pay the tax ; whilst~ eventua!ly~ a acw s[mr('e of revenue would he opened. W e are ~is,ly lavish iu the use of water, in order to preserve the property of our citizens in case of fire. Wouhl not the wisdom b(~equal, which should freely apply a portion of it to promote the (reation of proFerty, which otherwise may never come into existence
/Jn account of the Steam Engines now employed at Glasgow, and in i!.~ndffhbourhood. I',vlraclcd from ".~In ltistorieal account of the S!~u~ Enq'ine, and it,,;application in propelling vessels By Mr ]^~:s (.:L~:~.Ayl*, s~q~erintendant qf publie works for that city, ~nernber c~' its Chan~ber of Cbm'merce~ ~'c. ,~'c.'~Glasgow~ 1805. " T h e first Steam l';ngine erected in Glasgow, for spinning cot!~m; was l;ut up in January, 179~, in Messrs, William S~ott & Co.'s
103
of a~rial currents, hydrometrical observations may be made with great accuracy. In lieu of having points attached to the chyometer, as represented_in the figure, it may be as convenient to have two small holes9 for the insertion of the points of a pair of compasses, either of the common kind, of the construction used by clock makers, or that which is known under the name of beam compasses. The compasses may be used to regulate the opening of the sector, or to ascertaln~ by the aid of that instrun~ent, the comparative value of the distances which the rod of the chyometer has to be introduced into its tube. In order to convey an idea of the nature of the sector to any reader who may be unacquainted with it, I trust it will be sufficient to point out, that its construction is similar to that of the foot-rule used by carpenters. We have only to suppose such a rule, covered with brass~ and each leg graduated into 200 equal parts, in order to have an adequate conception of the instrument employed by me. A more particular explanation of the principle of the sector, may be found in any Encyclopedia, or Dictionary of Mathematics.
WATER WHEELS. On t h e construction o f water wheels a n d tile m e t h o d of applying t h e water for propelling them so as to produce t h e greatest effect.
7'0 the Committee of the Franklin Institute b~ PMladelphia. In constructing water-wheels, especially those of great power, the introduction of iron is a most essential improvement, and if this metal, and artisans skilled in tile working it, could be obtained at reasonable rates, water wheels might be made wholly of it, and prove ultimately, the cheapest, as if mana~edv with due care, .and worked with pure (not salt) water, they would last for centuries ; but as the first cost would 6e an objectlon~ I would recommend ia all very large wheels that the axis be made of cast iron, and in order to obtain the greatest strength with the least weight, the axis or shaft ought to be cast hollow, and in the hexagon or octagon form, with a strong iron flange to fix each set of arms and the cog wheel upon ; these flanges to be firmly fixed in their places with steel keys. On the adaptation of water wheels to the different heights of the water falls by which they are to be worked, I remark that falls of 9. to 9 feet are most advantageously worked with tile undershot wheel ; fall,s of 10 feet and upwards by tile bucket or breast wheel, which up to 20 or ~5 feet ought to be made about one-sixth higher than the fall of water by which it has to be worked ; and in wheels of both descriptions, the water ougl~t to flow on the wheel fi'om the
10']:
THE FR,'LNKLIN JOUft~NAL AND
surface of the dam. I am aware that this principle is at dh'ec~. variance with tim established pcactice, and perhaps there are few wheels in these states that can be worked as they are now fixed~ by thus applying the w a t e r ; the reasons will be apparent frora what lbllows. In adjusting the proportions of the internal wheels by whicl~ machinery is propelled, it is necessary, in order to obtain the greatest power, to limit the speed of the skirt of tim water wheel, so that it shall not be more than from 4 to 5 feet per second ; it havin~, been ascertained by accurate experiments, that the greatest fl~rce of water obtainable, is within these limits. As a falli~lg body, water descends at the speed of nearly 16 feet in the firs~ secoml, and it willappear evident that if a water wheel is required to be so driven, that the water with which it is loa,led has to descend 10, 11, or 19. feet per second, at which rates wheels are generai!y coust,-ucted to work, that a very large proportion of'the power is lost, or rather, is spent, in destroying, by unnecessary friction, the wht:el it is flowing upon. lu the common way of constructing mill work and of applying water to wheels, it has been found indispensably necessary to have a head of from ~ to 4 feet above the aperture through which the water ttows into the buckets, or against the floats of a water wheel, in order to be able to load the wheel instantaneously, anti without which precaution it could not be driven at the required speed ; from this circumstance it has been erroneously inferred that the impulse or shock which a water wheel so filled receives, is greater than the power to be derived fl-om the actual gravity of the water alone. This theory I have heard maintained among practical men, but it is, in ['act, only resorting to one error to rectify another. Overshot whei~ls have been adopted in numerous cases merely for the purpose of getting the water more readily into the b u c k e t s - - b u t con° tine the wheel to the proper working speed~ and that difficulty does not exist. In conseq~lence of the excessive speed at which water wheels are generally (h-iven, a small aecumulaticn of backwater either suspends or materially retards their operations, but by. properl,y confilfi~g their speed, the resistance from back water is cons~derably diminished and only amounts to about the same thing as worki~lg"from a dam as many inches lower as the wheel is immersed ; nnd in undershot wheels worked from a low head, or situated ir~ the tide-way, the resistance from back water may be farther obviated by placing the floats not exactly in a line from the centre of the wheel, but deviating 6 or 8 inches from it, so as to favour the water leaving the float ascending. In constructing water wheels to be driven at the speed of 4 to 5 feet per second, it will be requisite to make them broader to work the same quantity of water which is required to drive a quick speeded wheel. Thus if a person intending to erect a mill, has a stream sufi~icient to work a wheel 5 feet broad, the s k i r t to move ]0 feet per second, it is evident that if he wishes to work all th~
AMERICi~ ~,mct~Amcs* ,szat~AZt.~E. . . .
TO'~
water which such wheel takes, he must have his wheel 10 o r 12 feet broad, instead of 5, otherwise tile water must run to waste, as there would not be room in a slow moving wheel of 5 f e e t broad to receive more than half of it. 'File i;rineipal advantages resulting fi'om the prtq3osed method of adapting wheels to the falls by" which thoy are to be worked, and the method ofapplyiug water~ are : 1. The lessenin~ of triction upon the main gudgeons~ (and first pair of cog wheels,) t~y which, with a little care, they may be kept regularly cool, and the shaft or axis be preserved n{uch "longer in use than wl~en the gudgeons cannot be kept cool. • £ . By working water upon the principle of its actual gravity alone, aud applp.ing it ahvavs at the height of the surface of the dam, its power is d'ouble w~at is obtained by the common method of applyiu~ it. •% The exl~C;aslve penstock reqt~]ved ~,n convey the waler to tile w h c ( ' ] 5 , ~gCt!Cl'D.lly u s e d , x, I[~ li:tt b e lieCd(.,t! r i~+ {)Ii~.: illlich s]l;.tllt)*e,'el'?
and consequuntly less expr.~:~;ve, will be. ~ufftcient. 4. The resistance of back wa!er is reduced as fat" as possible. 5. The risk of Ih'e is less, as lhe lric~i,m is re-lueed. ] shall clo~e lhis paper with remarks upou th.'s~ e~tablishments I have inspected in the course of the presenl year. Mr. S m i t l e s n e w l y e v e c l t ' d corn mill tm lhe Rarito:a, at New.Rruuswick, N. J., has wa~or wheels 1~.; feet lfigh and 14 feet b l , a d , wifich ave worked l r. ( a hold . f f , ur feet. 'l'h~:~ater ~ t~eels lu,lke. 1~ rev ,lull( ~ ~ pet" tr, h!nlc, equal t(~ l0 feet lWl• second, when tile stones (five feet diamt, tev) make 100 |'evoh|tious. The water wheels at the flour mills at Braudywine, near W i l min~ttm, ave worked at the speed of 10 to 15 revolutions per mhlut% the Wheels ge,,leralty 16 feet hi/~h, and the fall 9.0 feet. iu all these establishment% Uaere is not obtained 30 pet" cent. of the Vtwer of the water used. 'l'he wa~er v¢l'~e~qsat F a i r Mount, used for supplying Philadelp]~i,~ with v,ater~ are 16 feet high anti 14 feet wide, worked by a head CA 5 feet; lhey are driven at tile ra~e of 15 revolutions i~er minute, which is equivalent to 11 feet per second for t h e ' m o t i o n of the skirt of the wheel. The machinery used here, is highly creditable to the workmen who put it up; but if the principle of applying water, which I have endeavoured to establish, be correct, it will be readily perceived, ~hat a very considerable loss of power is sustained by its mode.of applieafic~t. If these water wheels, as situated at present, were confined t~ mc-ke no more than 5 revolutitms per minute, and lhe pumps to lnake (lie same number of strokes that they now do, that is I 5 double strokes, tile water flowing agait~st (tie'wheel at the surface of lt~e dam ; each wheel would work two of the l:,umps, ~xill~ the watc.r that is r, ow taken to work one. But if the wt~eels were l)laccd I inches lower in the tide-way, two-thirds of the watery required 1~ work tree pump, would work two at equal speed, whih. the xxiwel continued free, and it would require no Iliore ihan i~ ut)\v ~scd t,~ "~'OL. [ , ~ . ~ O .
0 ,__L'I-|,,:V~I,i," ][t,>¢
I ~t
106
"r~g .~fLAN'KLINJOUR~.~L AND
work one pump, to work two with the wheel immersed 18 inches in the ~ide. This will. I trush be sufficiently clear, when it is consi,Jered, that by the reduced speed~ an addition of 150 per cent. in the quantity of water is thrown into the wheel and kept there, to~,~ed,er with the advantage gained between the water descending tour and ot~e-oighth ittstead of 11 feet per seco~d. Sel~lentber ~4, 18'25. W. P/tiC.KIN, Engineer,
STEAM E N G I N E S . The ~ubjoined account of the steam engines in use in Glasgow and it~ viciuity, at the. beginning ,)f the year 1825, exhibits a ereatio~ of physical force, applied to the p]~rposes of manufacturing, within the short space of thirty-three y~'ars, which is well worthy the notice of the cilv of Phila~felphia. The population of the two cities is nez~rlv equal, and the conviction is general, that we are well ~ituated f)w the business of manufacturing, and that our prosperity is intimately cotJnected with its establishment. Besides ~ho~e mat;~l'ac~ures extensively carried on in Glasgow~ there is one of vast importance, and which it is in our power extensively to pr,.,secute ; the manufacture of broad-ch)th and other fabrics of wool, eilher alt)ne or in mixture. Enough has been done in the United States, to prove that in nearly every department of that I)usincss~ blbour-saving machinery may be employed, with advantages ¢'qual to those exhibited in the manufacture of cotton. It is the detcr~z~iuali(m of the Editor to present'this subject more fully~ in a~l early I u btr d'this journal, as the views which it opens are t~-) mlmero~l~ and too important, to be dismissed in the compass of ,~ few l i r ~ e s .
'l'hc C~Wl>~)rat~onof ~be city would, it is believed, pursue a policy a~ wi~e as it ~voabl I)e libcr;~f, were they fi)r a limited time, to allow i~c fwc u,~e ~)f t!,~e Schuylkill water, for the supply of all the steam ~;~;,dm,~+, wl,.ich sh+~:;Id be built~ and applied to manufacturing purp,,-~'~, witi~i~ a c~,~'t,i~ period. This might be done without any iw('s~r~t loss ; v,l~ilst it w,,uld tend to give that activity to industry, ~,~hle to pr~q~erty, aml e~l)lo)ment to capital, which would immedi,~t~qy, alt!,~t~h it~directly~ more than pay the tax ; whilst~ eventua!ly~ a acw s[mr('e of revenue would he opened. W e are ~is,ly lavish iu the use of water, in order to preserve the property of our citizens in case of fire. Wouhl not the wisdom b(~equal, which should freely apply a portion of it to promote the (reation of proFerty, which otherwise may never come into existence
/Jn account of the Steam Engines now employed at Glasgow, and in i!.~ndffhbourhood. I',vlraclcd from ".~In ltistorieal account of the S!~u~ Enq'ine, and it,,;application in propelling vessels By Mr ]^~:s (.:L~:~.Ayl*, s~q~erintendant qf publie works for that city, ~nernber c~' its Chan~ber of Cbm'merce~ ~'c. ,~'c.'~Glasgow~ 1805. " T h e first Steam l';ngine erected in Glasgow, for spinning cot!~m; was l;ut up in January, 179~, in Messrs, William S~ott & Co.'s