SCIENTIFIC SUMMARY. 
679 
the 6th to the 10th, but was low on the 11th, the day of the maximum of 
heat. From the 10th to the 15th inclusive the wind was chiefly south. M. 
DeviUe remarks that this year the critical period of August was well marked, 
at least in the neighbourhood of Boulonnais, where the observations were 
made. 
The Tensile Breaking- strain of Atlantic Telegrajph Cables has been fully 
explained by Mr. Fairbairn, from whose published pamphlet we extract the 
following table : — 
SUMMARY OF RESULTS. 
Number 
Breakiner-weieht. 
Diameter' 
Elongation 
Elongation 
of 
in 8 feet 
detailed 
Description of Cable. 
of Cable, 
length of 
per unit 
experi- 
lb. 
tons. 
in inches. 
Cable, 
of length. 
ment. 
in inches. 
12 
Messrs. Silver & Co. ... 
130 
•058 
•35 
13 
J? 
Silver & Co. ... 
354 
•158 
•35 
• • • 
• • • 
1 
Duncan 
2,146 
2,258 
•958 
•77 
17-10 
•1781 
10 
Allan 
1-008 
6-75 j 
•0703 {a) 
•1380 \b) 
?? 
11 
Allan 
2,818 
1-258 
•67 
1-67 
•0169 (c) 
•0225 
2 
Hall & Wells ... 
4,946 
2-007 
•76 
2-16 
3 
?? 
Siemens & Co.,b. 
5,394 
2-408 
•77 
2-60 
•0270 
4 
Siemens & Co., A. 
5,730 
2-553 
•77 
2-85 
•0296 
5 
?? 
Glass, Elliott ... 
7,690 
3-433 
1-10 
3-77? 
•0392 ? 
6 
?? 
Glass, EUiott ... 
7,690 
3-433 
1-10 
4-10 
•0427 
7 
55 
W. F. Henley... 
9,594 
4-283 
•85 
1-85 
•0191 (d) 
8 
55 
W. F. Henley... 
12,786 
5-708 
•85 
2-72 
•0339 ie) 
9 
55 
Glass, Elliott, & 
Chatterton ... 
14,783 
6-600 
1-10 
3-57 
•0449 
(a) For outside steel wires. (d) Without outside covering. 
(S) For copper wires. (e) The completed cable. 
(c) The completed cable. 
Phenomena occurring during the Ebullition of Water. — M. Dufour, of 
Lausanne, who has so long and successfully examined the phenomena con- 
nected with the ebullition of water, has recently added some new facts to 
this subject. When water boils, the important part played by the air dis- 
solved in it is well known, Mr. Grove having shown that a bubble of steam 
is never produced without the liberation of an associated bubble of perma- 
nent gas, the air or one of its constituents. M. Dufour has now investigated 
the action of other gases, which are to some extent soluble in water, having 
tried hydrogen, carbonic acid, and coal gas. The conclusion at which he has 
arrived is that when water containing either of these three gases in solution 
is heated to the boiling point, in the presence and under the pressure of an 
atmosphere of each gas, the phenomena are nearly the same as if the liquid 
were boiled in air. His experiments show that the great difficulty with 
which gases leave the liquids which hold them in solution is due to a purely 
physical adhesion, and not to'any chemical affinity between the gas and the 
liquid ; in other words, it appears that no combination of the gas and the 
liquid takes place. 
