PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 407 



with adjusting screws are used to bind the spokes in the hub, 

 and also between the felloes, to expand them to the size of the 

 tire. A wheel may be taken to pieces to be repaired, and when 

 the tire is replaced, in a few minutes it can be drawn up as tight 

 as if drawn up by heat. 



Mr. Johnson stated that the ratio of strength had been found 

 to be one for cast iron, three for bronze, and five for puddled 

 steel. 



Mr. Wiard stated further that he considered it an error to 

 reduce the weight of the cannon in using steel. The recoil 

 would be increased by this. On the contrary, he should add to 

 the weight with the increased strength. 



Mr. Bliss moved that the subject of "Steel and-its Uses" be 

 taken up at the next meeting, in order that the question of 

 refining steel may be more fully considered. 



The motion was agreed to, and the Association adjourned. 



^ American Institute, Polytechnic Association, ) 



July 18, 1861. I 



Mr. Fisher was called to the chair. 



steel and its uses. 



. Mr. Bliss. — Probably there is no more valuable metallic 

 body than steel, and none of whose value we know so little, com- 

 pared with the advantages we have derived from it, and consid- 

 ering the time we have had to do with it. Few persons who use 

 steel are aware of the extent to which it may be refined and made 

 useful. About thirty-five years ago he had been called upon to ^ 

 perform an operation in dentistry wdiich he was unable to do, 

 because it involved the drilling of a hole in a solid piece of mate- 

 rial as hard as flint. The gentleman took it and in a few days 

 brought it back with the hole drilled in it. He ascertained who 

 had drilled it, and went to see him, and learned how it was done. 

 By working a pound of steel under the hammer, he had refined it 

 so that he could make drills to " go through anything." Another 

 gentleman tried the same experiment, and made a drill which he 

 passed through the blade of his pocket-knife, without drawing the 

 temper of the knife at all. In Boston, he noticed that the tools 

 of a carver from England were left unfinished; and the carver 



