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Description of a new machine for drawing solid metal tubing
,~olid ,Metal Tubing.
407
that a ship's crew could readily carry out the process at any place where they could land and animals were abundant, and thus lay in a store of meat which, although, no doubt, salted to a certain extent, would not have the same disadvantages in a sanitary point of view as meat preserved in brine-pickle. Some lengths of india-rubber tubing, pieces of metal tube with stop-cocks, and tubs for holding the liquid, are all that is required. In hot climates the drying may be effected in the open air, arid in other cases there would be no difficulty in arranging a room for the purpose, either on shore or on board ship.
.Description of a New 3laehine for drawing Solid Metal Tubing. I~'rom the Journal of the Society of Arts, No. 589,
A new machine for drawing solid metal tubes has lately been tested in London with considerable success. The system was originally introduced into England by a French gentleman, about ten years ago, but in consequence of defective mechanical arrangements was at that time unsuccessful. The Stephenson Tube Company have lately erected extensive works at Birmingham for the manufacture of brass and copper tubes on this principle, but the new machine is especially adapted to the formation of tubes of steel, and other hard and close-grained metals. The ordinary method of forming wrought iron tubes is by bending round a long narrow plate of the metal so that the edges meet, and then having reduced them to a welding heat, to join them together by drawing the tube through a die made for that purpose. The machine in question entirely differs from this, and its action may be described as follows : - - I t consists of two large cast iron cylinders, 11 feet long, placed opposite each other, and connected by a ram of 10 feet travel, which is driven out of the one and into the other alternately. On each end of the cylinders is a massive flange, pierced with eight holes, some four inches across ; on the ram is a similar flange, but double, offering eight holes to each cylinder. The diameter of this hydraulic ram is 169 inches, and the force obtainable upwards of 600 tons. A drawplate or die of peculiar form is placed in one of the holes in an inner flange of one of the cylinders, and the tube to be drawn slightly tapered at the end, to allow of its passing into the die, is placed therein, having previously received a steel-headed mandril, intended to act on the interior of the tube. The tube is fixed on the flange of the ram by means of a screw pin projecting through the flange of the cylinder, and the stem of the mandril is fastened to the further end of the cylinder. The water being forced into the cylinder the ram is driven forward, and the tube is drawn bodily through the die, or draw-plate, and over the mandril, the head of which, inside the tube, is placed within the circle of contact of the die outside. By this means the tube is drawn externally and internally at the same time, and an eighth of an inch of steel may, at a time, be displaced from the surface, the tube being elongated proportionately; but in practice it is found more convenient co take off less at each pass in order to avoid fatiguing the metal overmuch. It is stated that two bars of rough iron, as delivered from the forge, 3~x inches diameter and 4 feet long, were placed
408
d~lechanics, Physic% and Chemistry.
in the machine and drawn through the die, the drawing occupying some five minutes. The bars issued from the die with a surface finer than carl be obtained at present by a n y k n o w n mechanical means, except continued friction, and infinitely truer t h a n a n y t u r n i n g - l a t h e produces. I t wouhttake a man at a lathe two days at least to t u r n these bars, and he would rhea produce inferior results to those obtained in perhaps a q u a r t e r of an hour, if the time employed to fix and unfix the bars in the hydraulic d r a w i n g bench be included. I t will scarcely be necessary to remark, in conclusion, that st~ould this machine fulfil the expectations of the inventor, it will cause a complete revolution in the manufitcture of gun-barrels, hollow shafting, axles, piston-rods, and such-like articles.
To make an Absolutely Correct Camera copy era Uhart by 11[eans era * Single dDistorting Lens.* B y ROBEr~T If. Bow, C. E. From the Lend. Cir. Eng. and Arch. Jour.~ December, 1863.
I have already mentioned before this society that distortion in a negative may be corrected in the positive taken from it by the camera, whether the distortion arises from the defects of the lens, or from the camera not having been placed squarely to the object in t a k i n g the negative. This short paper is merely to call a t t e n t i o n to a ver~ simple practical application of the method of correcting that distortion which arises from the defeets of the lens. I have here a camera with an achromatic plane-convex lens of 4½ ins. focal length. I t produces pictures which, if of moderate size, are free from a n y t h i n g that a casual observer would detect as distortion ; but the following table will give you an idea of the real a m o u n t thereof. Before you I have ]aid a negative taken by the same lens, embracing a field of 80 ° . Table showing the Distortion of Scale (measured in the direction of a diameter of the picture) when a distantt view is taken with the plane-convex achromatic lens of four and a half inches foeal length, described at page 241 of the current volume of The Civit ~b~ngineer~;~d Arc/~itect's Journal, the stop being three-quarters of an inch from the fla~ ~ide. (The points in the image corresponding with thepenoils at the several angles of obliquity, are obtained by the method referred to in roy paper on the " Curvatltrcs of the linage.")
Between rays .... ,, ,, .... ,, ,, ,, ,, ,, ,,
at 0° and 5° 5° ,' 10° 10° " ]5° 15° ', 2i~° 20° ,, 25° 25° ,,31, ° 30o ,,35 °
Intervals measured (approximately) from the actual image,
Intervals according to calculation when there is no distortion.
100 101 102 10~ 105 107 lli)
100.00 101'54 104"78 109'75 116-97 126'93 140'42
F r o m this table it :~ppears, then, that an object l y i n g between 30 ° and 35 ° of obliquity will suffer a contraction from 140"42 to 110, or a diminution of 30'4 `) upon u length of 140'42, which is equivalent to Read at a meeting of the Edinburgh t'hoiographic Society, 21st October, 18~3. ]-When the object is not so distant, the distortion will be somewhat greater.
407
that a ship's crew could readily carry out the process at any place where they could land and animals were abundant, and thus lay in a store of meat which, although, no doubt, salted to a certain extent, would not have the same disadvantages in a sanitary point of view as meat preserved in brine-pickle. Some lengths of india-rubber tubing, pieces of metal tube with stop-cocks, and tubs for holding the liquid, are all that is required. In hot climates the drying may be effected in the open air, arid in other cases there would be no difficulty in arranging a room for the purpose, either on shore or on board ship.
.Description of a New 3laehine for drawing Solid Metal Tubing. I~'rom the Journal of the Society of Arts, No. 589,
A new machine for drawing solid metal tubes has lately been tested in London with considerable success. The system was originally introduced into England by a French gentleman, about ten years ago, but in consequence of defective mechanical arrangements was at that time unsuccessful. The Stephenson Tube Company have lately erected extensive works at Birmingham for the manufacture of brass and copper tubes on this principle, but the new machine is especially adapted to the formation of tubes of steel, and other hard and close-grained metals. The ordinary method of forming wrought iron tubes is by bending round a long narrow plate of the metal so that the edges meet, and then having reduced them to a welding heat, to join them together by drawing the tube through a die made for that purpose. The machine in question entirely differs from this, and its action may be described as follows : - - I t consists of two large cast iron cylinders, 11 feet long, placed opposite each other, and connected by a ram of 10 feet travel, which is driven out of the one and into the other alternately. On each end of the cylinders is a massive flange, pierced with eight holes, some four inches across ; on the ram is a similar flange, but double, offering eight holes to each cylinder. The diameter of this hydraulic ram is 169 inches, and the force obtainable upwards of 600 tons. A drawplate or die of peculiar form is placed in one of the holes in an inner flange of one of the cylinders, and the tube to be drawn slightly tapered at the end, to allow of its passing into the die, is placed therein, having previously received a steel-headed mandril, intended to act on the interior of the tube. The tube is fixed on the flange of the ram by means of a screw pin projecting through the flange of the cylinder, and the stem of the mandril is fastened to the further end of the cylinder. The water being forced into the cylinder the ram is driven forward, and the tube is drawn bodily through the die, or draw-plate, and over the mandril, the head of which, inside the tube, is placed within the circle of contact of the die outside. By this means the tube is drawn externally and internally at the same time, and an eighth of an inch of steel may, at a time, be displaced from the surface, the tube being elongated proportionately; but in practice it is found more convenient co take off less at each pass in order to avoid fatiguing the metal overmuch. It is stated that two bars of rough iron, as delivered from the forge, 3~x inches diameter and 4 feet long, were placed
408
d~lechanics, Physic% and Chemistry.
in the machine and drawn through the die, the drawing occupying some five minutes. The bars issued from the die with a surface finer than carl be obtained at present by a n y k n o w n mechanical means, except continued friction, and infinitely truer t h a n a n y t u r n i n g - l a t h e produces. I t wouhttake a man at a lathe two days at least to t u r n these bars, and he would rhea produce inferior results to those obtained in perhaps a q u a r t e r of an hour, if the time employed to fix and unfix the bars in the hydraulic d r a w i n g bench be included. I t will scarcely be necessary to remark, in conclusion, that st~ould this machine fulfil the expectations of the inventor, it will cause a complete revolution in the manufitcture of gun-barrels, hollow shafting, axles, piston-rods, and such-like articles.
To make an Absolutely Correct Camera copy era Uhart by 11[eans era * Single dDistorting Lens.* B y ROBEr~T If. Bow, C. E. From the Lend. Cir. Eng. and Arch. Jour.~ December, 1863.
I have already mentioned before this society that distortion in a negative may be corrected in the positive taken from it by the camera, whether the distortion arises from the defects of the lens, or from the camera not having been placed squarely to the object in t a k i n g the negative. This short paper is merely to call a t t e n t i o n to a ver~ simple practical application of the method of correcting that distortion which arises from the defeets of the lens. I have here a camera with an achromatic plane-convex lens of 4½ ins. focal length. I t produces pictures which, if of moderate size, are free from a n y t h i n g that a casual observer would detect as distortion ; but the following table will give you an idea of the real a m o u n t thereof. Before you I have ]aid a negative taken by the same lens, embracing a field of 80 ° . Table showing the Distortion of Scale (measured in the direction of a diameter of the picture) when a distantt view is taken with the plane-convex achromatic lens of four and a half inches foeal length, described at page 241 of the current volume of The Civit ~b~ngineer~;~d Arc/~itect's Journal, the stop being three-quarters of an inch from the fla~ ~ide. (The points in the image corresponding with thepenoils at the several angles of obliquity, are obtained by the method referred to in roy paper on the " Curvatltrcs of the linage.")
Between rays .... ,, ,, .... ,, ,, ,, ,, ,, ,,
at 0° and 5° 5° ,' 10° 10° " ]5° 15° ', 2i~° 20° ,, 25° 25° ,,31, ° 30o ,,35 °
Intervals measured (approximately) from the actual image,
Intervals according to calculation when there is no distortion.
100 101 102 10~ 105 107 lli)
100.00 101'54 104"78 109'75 116-97 126'93 140'42
F r o m this table it :~ppears, then, that an object l y i n g between 30 ° and 35 ° of obliquity will suffer a contraction from 140"42 to 110, or a diminution of 30'4 `) upon u length of 140'42, which is equivalent to Read at a meeting of the Edinburgh t'hoiographic Society, 21st October, 18~3. ]-When the object is not so distant, the distortion will be somewhat greater.