578 
POPULAR SCIENCE REVIEW. 
Kirchoff has published in the “Philosophical Magazine” for April 
“ Some Contributions toward the History of Spectrum' Analysis,” in which 
he reviews the parts taken by various investigators in the development of 
this subject. In the same number is a short note by Dr. Roscoe, “ On the 
Spectrum produced by the Flame evolved in the Manufacture of Cast Steel 
by the Bessemer Process.” The author expresses his belief that this 
first practical application of spectrum analysis will prove of the highest 
importance in the manufacture of cast steel by this method. 
Dr. Joule also describes a new and extremely sensitive thermometer, 
lie states that it is able to detect the heat radiated by the moon. The 
instrument consists of a vertical glass tube, two feet long and four inches 
wide, closed at the bottom end, and divided longitudinally by a blackened 
pasteboard diaphragm, leaving a space at each end about an inch in length. 
A magnetized sewing-needle is suspended over the edge of the division at 
the top. The slightest excess of temperature of one side over that of the 
other occasions a circulation of the air up one side and down the other, 
which in doing so moves the index. 
Mr. G. Gore, of Birmingham, has produced a new and simple furnace 
capable of smelting cast-iron, copper, gold, &c., without the aid of a 
bellows or lofty chimney. Its heat is generated by ordinary coal-gas and 
atmospheric air ; its consumption of gas is from 30 to 40 cubic feet per 
hour ; “ it has smelted five ounces of copper in four and a quarter minutes, 
and is capable of fusing half a pound of copper or six ounces of cast- 
iron;” its size is about that of a Stilton cheese; and it possesses the 
valuable qualification of continuous access to the contents of the crucible 
for any length of time without oxidizing it or materially lowering its 
temperature ; the crucible may also be removed or a fresh one introduced 
without interfering with the action of the furnace. 
Some additional experiments “ On the Motion of Vapours towards the 
Cold” is given by C. Tomlinson in the May number of the “Philosophical 
Magazine.” They consist of a few of the subsidiary facts observed during 
his previous inquiry, which we have already noticed in a previous number 
of this Review. 
Mr. W. R. Grove, F.R.S., has recently delivered a lecture to the Chemical 
Society, “ On the Action of Heat upon certain Fluids.” His observations had 
reference more particularly to the bumping action observed whilst boiling 
water which has been deprived of its dissolved air. We know that if water 
has been deprived of air by means of an air-pump, or by means of long- 
continued boiling in a vessel with a very narrow mouth to exclude the 
atmosphere, the application of heat is not attended by constant and regular 
ebullition as when water is boiled in a wide open vessel, but the water is 
for a short time quiescent, and then suddenly at intervals evolves explosive 
bursts of steam ; and a thermometer immersed in the water shows a 
variable temperature, hottest just before an explosion and least hot imme- 
diately after. A consequence is that no one has yet been able to observe the 
true boiling-point of water. 
The lecturer found that on boiling ordinary water, air containing a 
slightly increased proportion of oxygen was first driven out ; the proportion 
of oxygen then gradually diminished until pure nitrogen was expelled. 
