402 Scientific Intelligence. 
to cause the absorption mek has generally meee ogden to 
layers of the atmosphere than the chemical se hitherto 
adopted.—Annalen der Physik und Chemie, No. 3, 
13. Conversion of Radiant Energy into nc ous Febeatioste 
—Mr. WititaAm Henry Prexce, in a paper read at the Royal 
Society, March 10th, gives the details of numerous ee 
upon the effect of intermittent beams of light in producing sono- 
rous vibrations. It was found that their vibrations were not pro- 
duced by the dise varies received the intermittent beam, but were 
due to the motion of the air contained in the hearing tube, for the 
moands were louder without the disc than with it. These sounds 
m 
tions were due to the motion of the a A microphone was then 
sc Tan for the interrupter, and a was found that the appara- 
tus served as a sig — and articulate ca was 
ie, ee —Nature, March 24, 18 T. 
ellites’ orbits are all supposed to be in one plane. ude — is 
formed of homogeneous viscous fluid, but a large part of t 
ere 
It is then proved that if # be the whole energy, both kinetic 
and potential, of the system, and if § be a function of the dis- 
tance of any one of the satellites from the lan (which function, 
when the mass of the satellite is small compared with that of the 
planet, is the } power se ror distance), the equation expressive of 
the rate of change of 
where ¢ is the time, A a certain constant, and 6 expresses partial 
differentiation, 
A similar equation applies to each satellite, and the whole of 
