97 
Ordinary Meeting, January 24th, 1871. 
E. W. Binney, F.R.S., F.G.S., President, in the Chair. 
Mr. Brothers, F.RA.S., exhibited a drawing from the 
fine photograph of the solar Corona, taken by him at Syra- 
cuse, during the late total eclipse of the Sun. 
Mr. W. B. Johnson, C.E., gave an account of two cases of 
very narrow escapes from serious accident to railway trains, 
in consequence of the present faulty system of arrangement 
of the points or switches. 
Dr, Joule, F.R.S., &c., read the following letter, dated 
January 21st, 1871, which he had received from Mr. 
William H. Johnson, of Bowdon. 
“ Since the last meeting of the Philosophical Society I 
have made some further experiments on the ‘Effect of cold 
on the strength of Iron.’ 
In these I have maintained a nearly fixed temperature, 
and thus avoided to a great extent the error occasioned by 
the rise in temperature, consequent on sudden torsion. 
January 11th. A piece of a charcoal wire rod, •237 of an 
inch diameter, gave the following results: — 
1st. 2nd. Srd. 
At about 40° F 20 twists ... 19 twists ... 17 twists. 
Adjacent 6" at tempe- 
rature of melting 
zinc 10 twists ... 9 twists ... 1\ twists. 
4th. 6th. 
Twisted very slowly, surrounded by salt 
and snow ' 19 \ twists ... 16 twists. 
Adjacent 6" at about 40° F 15 twists 
The twisting under salt and snow was performed so 
slowly, each experiment lasting a quarter of an hour or 
more, that the temperature cannot have been affected by 
the torsion. The same care was taken at the temperature 
of 40° F. 
Peooeedinos — Lit. & Phil. Soc. — Voi. X. — No. 9.— Session 1870-71. 
