SCIENTIFIC SUMMAKY. 
327 
The Temperature of the Air^ and that of Trees and Forests. — In a paper 
sent in to the Frencli Academy on March 29, M. Becquerel gave an account 
of some curious inquiries recently conducted by him on this point. He 
stated that in severe cold in winter, when the temperature falls to 8°, 10°, 
and further below zero, it is colder in woods than outside them. M. Bec- 
querel the elder has taken this question up again, with the aid of observa- 
tions which he made in 1858 and 1859 with the electric thermometer on the 
temperature of the air in the north, compared to that of a tree of Om. 45 in 
diameter, to Om. 22 below the bark. In the month of July, at the time of 
the greatest heats, the temperature in the air was successively at 2940, 
28*20, 26*95, &c. • whilst in the tree on the same days the register was 
24*60, 25*90, 25*40, &c. ; the differences were equal to 4*80, 2*30, and 1*55, 
always diminishing. Once the temperature of the air, at the end of several 
days, reached 18*78 ; that of the tree was, on the contrary, higher, as 
follows : — 24*65, 23*50, 21*50. These results show that a certain time is 
necessary for the heat to penetrate the tree, but without attaining the maxi- 
mum temperature of the air, except in certain peculiar circumstances 
already set forth. The observations recorded further show that in summer 
the temperature of the air is in general^higher at nine o’clock at night than 
at nine o’clock in the morning, and even frequently higher than at three 
o’clock. This is a proof that the maxima only occur rather late in the 
evening. 
A new Oxyhydrogen Lamp. — Les Mondes (May 6) gives an account of 
some experiments which are given nightly at Paris in illustration of the 
qualities of a new lamp. The burner, which is arranged to burn either 
pure hydrogen gas or coal gas at any pressure from two millimetres up to 
several centimetres, is constructed in the following manner : — The oxygen 
issues from a central opening ; the hydrogen or coal gas issues from small 
tubular openings not unlike those met with in the Leslie gas-burner j but 
instead of being as in that burner almost vertical, they are in this instance 
bent so as to lay almost horizontal, and thus stand with the openings 
opposite to each other, while the oxygen is in the centre j the flame is 
directed against a piece of zircon-magnesia. We further notice a circular 
Argand burner without any magnesia cone, and so arranged as to have the 
combustion of the gas supported by oxygen gas instead of by air. A modi- 
fication of this burner, as regards the arrangement of the supply tubes, is 
made to serve for burning gas fed by oxygen, the burner being placed in 
strong glass globes so as to suit the purposes of lighting mines and for 
submarine lamps. Care has been taken by proper and suitable means to 
carry off the products of the combustion in each case in such manner as to 
insure the safe use of the apparatus. 
ZOOLOGY AND COMPAKATIVE ANATOMY. 
The Mole CricLet. — Those who are interested in this group will be glad 
to learn [that Mr. S. Scudder, the well-known American entomologist, has 
written a very valuable memoir on these insects. It is published by the 
