MEMOIR OF DANIEL THEADWELL. 521 



cylindrical projection is formed upon tlie back sides of the sets k and e. The projection of one of the 

 sets passes into the hole in the spindle n, the projection of the other set passes into the hole in the spin- 

 dle L, by which means the sets are supported by the respective spindles, f is a swage, or die, made of 

 cast iron, the face of which forms about one third of a hollow cylinder, and is placed opposite the i)in d. 

 G is a plate of cast iron suspended by a chain from any fixed point above it, and connected with the 

 handle i. The part of this plate which is opposite the pin d forms part of a hollow cylinder correspond- 

 ing to the diameter of the pin d. 



To use this machinery, the bar of iron, which has passed through the winding machinery, being 

 heated in the furnace to a welding heat, is carried to the press upon which the machinery just described 

 stands, and placed upon the pin d with the tapering or wedge-like ends, which now lap over each other, 

 between the pin d and the swage or die f. The plate of cast iron g is then placed between the pin d 

 and the set e, as is seen in Fig. 7. The press is then put in operation, by which the spindle l is moved 

 towards the pin d, and with it moves the swage or die f. B3' this motion the overlapfjing ends of the 

 circular bar are pressed together and lirmly welded to each other. 



With the same machinery rings already formed may be enclosed in larger rings, until any required 

 thickness is obtained, and, after being heated to a welding heat, they can be firmly welded in the press, 

 and united to other similar cylinders until the requisite length is obtained. 



Patent enrolled 20th June, 18-16. 



IV. — See page 4'10. 



FRENCH REPORT ON TREADWELL'S 32-POUNDER, MAY, 1848. 



[Translation.] 



By order of the Due dc Montpensier a commission was appointed, April 4, 1847, to test the 

 cannon of wrought iron and steel made and presented to the Government b}- Mr. Daniel Treadweli, 

 Professor of Mechanics in the United States. This commission was composed of five officers of artil- 

 lerj'. The following is an abstract of the report. 



A programme arranged 113- the committee of artillery- indicated the nature, course, and manner of 

 procedure in this proof, article bj' article, with all the necessary directions. To this the commission 

 has scrupulously conformed. 



The external examination of the gun showed no cracks nor fissures. The turning was accurate, 

 leaving only slight annular traces of the process of manufacture. The trunnion rings were perfectly 

 screwed and riveted on the gun. 



Interior examination with a mirror showed that the piece was perfectlj' sound without any honey- 

 comb, fissure, crack, scratch, or marks of tiie borer. The examination at L'Etoile, and all the other 

 examinations during the proof, indicate only the slightest difliercnces in diameter, which in view of the 

 frequent variations in the plaj' of the gauge should be attributed to its imperfection rather than to the 

 boring of the gun. 



The table annexed to this report gives by simple inspection all the facts and results of firing 800 

 rounds in five series. Two prominent observations are in evidence from the comparison of the circum- 

 stances of this firing with those of the examination at L'Etoile : — 



1st. The good comluite of the metal, and its resistance to these 800 rounds, which is shown b}' the 

 perfect condition of the whole bore. 



2d. The remarkable accuracy of the fire of the gun. The number of buirs-e3-es (blancs) hit in 

 a series of fift}' rounds led to the anticipation of great accuracj- of firing, but it was necessary to be 



