TRANSACTIONS OF SECTION Cf. 7G7 



Having carried out a progressive series of experiments on a steamer, it becomes an 

 easy matter to modify the design of the existing propeller so that its maximum 

 efficiency shall occiu; at the working speed of the ship. The maximum efficiency 

 of a screw-propeller is about 70 per cent. ; in the experiment carried out, it was 

 70 per cent, at 4 miles per hour, and oQ at 7 miles per hour. 



4, A Modem Power Gas Plant Working in a Textile Factory. 



By H. Allen. 



5. Effect of Temperature in Varyiny the Resistance to Impact, the 

 Hardness, and the Tensile Strenyth of Metals. By A. Macphail. 



