Proceedings of the British Association. 283 



Section G.— MECHANICAL SCIENCE. 



So many distinguished engineers were detained in London, in 

 attendance on committees of the House of Commons, that this Sec- 

 tion met on Thursday and Friday only to adjourn. Other members, 

 who had run down for a day or two, were obliged to return ; and so 

 few were in attendance when the Section met on Saturday for busi- 

 ness, that it was thought best merely to read the few papers received, 

 and then close the Section. In reference to this subject, we have 

 received the following letter : — 



You will oblige me by stating, that I was prepared to lay some 

 remarks before Section G ' On the experimental determination of the 

 Strength of Wood and Cast-iron,' but the attendance was so small 

 owing to the immense quantity of business keeping those who are 

 interested in engineering in London, and had been so small all the 

 week from that reason, that Prof. Willis advised me to reserve my 

 paper, and on this suggestion I acted. If you will state this, or 

 something to this effect, you will oblige yours, &c. 



M. Cowie, 

 Principal of the College of Engineers, Putney, Surrey. 



The first paper read was, c On a new method of converting Recti- 

 linear into Rotatory Motion,' by Dr. Booth. — The object of the com- 

 munication was to show the applicability of a new species of crank, 

 termed by the inventor the sliding crank, to the steam engine, more 

 especially in those cases where space is an object of primary con- 

 sideration. One of the most important improvements effected by this 

 motion is, that the distance between the shaft and the top of the 

 cylinder is only one-half the length of the stroke. Other advantages 

 pointed out in the course of the paper were, that the friction on the 

 sliding parts is nearly insensible ; that almost all the parts of the 

 engine have a rotatory instead of a reciprocating motion : that all 

 the subsidiary parts of a low-pressure engine are worked with great 

 simplicity ; and that in this construction, a longer stroke than in any 

 other of the same dimensions may be introduced, and the expansive 

 principle more fully developed. 



