MEMOII1 OF DANIEL TREADWELL. 



517 



2,600 + 12.000 = 14,600 -~ 156.6 = 93.2 lb., 



ilh 



quantity under these circumstances upon cars with 3-inch gudgeons than is required lor transporting 



the same quantity upon cars with If in. gudgeons. This calculation is founded upon the supposition 

 of the transportation being upon a level railway. Let us take the case of ascending a plane of thirty 



Wor 



O 



such planes, and such engines will draw any loads upon the levels winch they can carry over the ascents. 

 Take, therefore, a car, gudgeons 1£ in, diameter, weight 2,000, load 0,000 lb., and we have for the resist- 

 ance upon the level, as has been before seen, a traction of 40.5 lb., and tor elevating tin- load only on a 

 thirty feet inclination T ^th part of the weight. Then *&$ = 48.8, and 48.8 + 40.5 = 89.3 lb. traction 

 up the plane. A load of 12,000 lb. upon a car weighing 2,G00 lb., gudgeons 3 in. diameter, has been 

 found to require upon a level a force of traction of 93.2 lb. ; add to this If $££ = 83 lb. for elevating the 

 load, and we have 83 + 93.2 = 176.2 for the traction in this last instance. That is, we have in useful 

 effect a transportation in the first case of 6,000 lb. by a traction of 89.3 lb., and from the last a transpor- 

 tation of 12,000 lb. by a traction of 176.2 lb. Or a double load moved up the inclined plane by a very 

 little less than a double force. 



Very respectfully yours, 



Daniel Tread well. 



Boston, March 25, 1837. 



III. — See page 409. 



IMPROVEMENT IN MACHINERY FOR WELDING AND FORMING WROUGHT IKON 



CANNON. 



Fig. 1 is a longitudinal section of such machinery shown in elevation. Fig. 2, a plan of the same 

 machinery in section. Figs. 3 and 4 are cross sections made through parts which will be described. 



aaa a represents the frame of a h} T drostatic press ; the upright pieces (Fig. 1) are heavy pieces of 

 cast iron, and the horizontal pieces are bars of wrought iron. The top bars are supported by straps pass- 

 ing round deep pieces of timber. 



b b, a large cast iron bed-plate having two rails projecting upwards, as shown at Fig. 3 and 4 in cross 

 section, upon which the chair x, hereafter to be described, can be moved lengthwise, cc, cylinder of the 

 press hooped with wrought iron ; d, piston ; seen in cross section at Fig. 3. The piston or ram has a 

 cylindrical cavity running nearly through it. ee (Figs. 1 and 2), a cast iron guide-box bolted to the 

 head of the cylinder to direct the forward and backward movements of the piston, f f, pipe leading 

 from the pump of the press to the cylinder d. gg, system of weights and bent levers to draw back the 

 piston when the water leaves the cylinder, mi, a cast iron spindle resting upon the cast iron chair, n. 

 A hole somewhat larger than the cannon to be formed runs through this spindle, and one end of the 

 round bar of iron, or backing pin, k k, may be run through this hole, ll, a spindle similar to ii n, bolted 

 upon the end of the piston. The mandrel, a punch, mm, passes through this spindle. This mandrel is 

 connected with the rack, nn, one end of which passes into the cavity of the piston, and can be moved 

 backwards and forwards in that cavity by means of the crank and axle oo, and the pinion p. When the 

 rack is passed out of the cavity of the piston, it passes into the hole made through the spindle ll, and 

 carries the mandrel mm through and out of the spindle ll. This mandrel is somewhat conical, being 

 about a quarter of an inch larger at the end next the rack than at the other end. r, r, r, r, are blocks of 

 cast iron having a bottom and two sides projecting upwards so as to leave a rectangular cavity in which 



* This 156.6 lb. is found as follows. Of the 15,820 lb. carried in Nos. 1 and 3, 4,670 upon the small gudgeons required 

 a force of traction upon a level of -^f- - 22 lb., and the remaining 11,150 required a force of traction of 93.2 -22 = 71.2 lb. 

 Hence *W$* = 156.6. Or jM t tha of the load. 



