276 Proceedings of the Poyal Society of Edinburgh. [Sess. 
been given of the effects of liquid air on alloy B both in the cast and in the 
quenched condition. Similar tests were now made with alloy D. As it 
had been found that quenching of such bronzes at temperatures exceeding 
600 C. produced cracking of the material, the quenching was carried out at 
Fig. l. 
450° C. Fig. 1 exhibits the results obtained. While the most important 
point here is the percentage changes produced by the varying treatment, 
the absolute values of the intensity of magnetisation (I) and the strength of 
the magnetising field (H) are also given for facilitating comparison with 
other materials. In calculating H, allowance has been made for the end 
effect of the magnetising solenoid, and Du Bois’s factors * are employed in 
* Du Bois, Magnetische Kreise in Theorie und Praxis , Berlin, 1894. 
