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hoff’s explanation is in no way astronomical, and is unsupported by obser- 
vation. In referring to bis own theory of solar reflexion and parallax, he 
has confirmed the fact, which passed unnoticed up to the present time, that 
when, after the apparition of a beam or fillet of light thrown from one side 
do the other, a spot is divided into two parts, one of the halves, as if it had 
received an impulse in front, takes an abnormal motion of its own, while the 
other half continues alone its normal movement, with variations of velocity 
which only depend on the latitude. 
The Laws of Isolation. — M. G. Lambert read a paper before the French 
Academy on January 28. The memoir referred especially to the tempera- 
ture of the Arctic zones, and to the power exerted by the diurnal isolation 
■of the sun, the principal cause of this temperature. The power of isolation 
in a certain place ought not to be confounded with the thermometric effect 
which is its consequence, but which depends upon a number of variable 
causes analysed by the author, and of which the technical details have been 
sent in an extended memoir upon isothermic lines, &c. Designating by 
L the heliocentric longitude of the sun, w = the obliquity of the ecliptic, 
w'= the angle formed by the axis of the earth with the circle of isolation, 
un angle which is equal to the declination, l = the latitude, we have the 
following equations to represent the graphic trace of the curve of isolation 
at each parallel and at each season: — 
Sin w'— sin w sin L 
x — L cos ( l—w ') 
y — L cos {l— tv') tan w' Sw ( l—w ' ) 
in which x represents the power of the diurnal isolation. 
The French Academy's Prize for Astronomy has been awarded to Mr. 
MacLear, for the mensuration, at the Cape of Good Hope, of an arc of the 
meridian, and the publication of his great work, a Verification and Extension 
of La Caille’s Arc of Meridian at the Cape of Good Hope,” two vols., 4to. 
The celestial amplitude of the arc measured by Mr. MacLear differs only by 
a small fraction of a second from the amplitude found by La Caille, and this 
agreement contributes to maintain the reputation of the French astronomer. 
The Cometary Theory of Shooting- stars — to whom does it belong ? — The 
Abbe ^Moigno, who has broached this question, and who evidently feels 
-strongly on the point, makes the following observations in our contemporary, 
the Chemical News, of March 15 : u In a quite recent note inserted on March 
3, in the International Bulletin of the Imperial Observatory, and on the 8th 
inst. in the Bulletin of the Scientific Association of France, M. Le Verrier 
resumes on the cometary theory of shooting stars, and persists in attributing 
the honour of it to himself, without condescending to mention the name of 
Schiaparelli, whose letters, however, have been published in a journal of 
great authority, the Meteorological Bulletin of the College of Borne, issued 
under the superintendence of the Bev. P. Secchi, and were translated by the 
writer before M. Le Verrier had published a single word of his researches. 
We are really frightened by this system of organized cool-blooded appro- 
priation, and more so by these lines, the effect of which has been even more 
coolly calculated : Sir John Herschel , who, along with his son, Alexander 
Herschel , has paid great attention to shooting-stars, gives his complete assent to 
