28 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



give a correction of + 1.81", and ten observations of the reap- 

 pearance at the bright limb one of + 1.31". For the purpose 

 of investigating the probable cause of these differences, Mr. 

 Neison states that he is extending his calculations to a laro-e 

 number of observations. But, as a preliminary theoretical 

 explanation of this difference, he submits a highly interesting 

 and suggestive note on the existence of a lunar atmosphere 

 of extreme tenuity ; and shows that, if such an atmosphere ex- 

 ist, having a density, at the surface of the moon, of only 4 - 

 part of the density of our own atmosphere, there would be 

 at the dark limb of the moon a horizontal refraction of about 

 one second, while at the bright limb the horizontal refraction 

 would amount to less than half a second. These results he 

 considers confirmatory of the idea that the difference between 

 the occultation and telescopic diameters has its origin in the 

 presence of a lunar atmosphere. He furthermore disposes of 

 all the various more or less ill-founded objections that have 

 been raised as to the existence of a lunar atmosphere, but with- 

 out considering that he has yet been able actually to demon- 

 strate its presence. Monthly Notices Roy. Astron. Soc, 1873, 

 XXXIV., 6-16. 



EXPLOSION OF A METEOR. 



In the proceedings of the Royal Society of London for 

 January 23, 1873, is an account of a meteor which burst 

 against a British light-vessel not far from the Scilly Islands, 

 scattering a shower of cinders on the deck, which were 

 crushed under the feet of the sailors as they walked. Noth- 

 ing was observed before the shock, but immediately after it 

 balls of fire, like large stars, were seen falling into the water, 

 resembling splendid fireworks. The seamen reported that 

 there was a decided smell of brimstone, although it is thought 

 this may have been imaginary. The cinders were, unfortu- 

 nately, all washed off the deck by the rain and sea before 

 daylight, so that no specimen was preserved. JPr. Hoy. Soc. 

 London, 1873, XXL, 122. 



THE CONSTITUTION OF COMETS. 



Dr. Vogel has reviewed the results of the spectrum analysis 

 of the light of the comets that have appeared since 1864. 

 None of these have been remarkable for their brilliancy, and 



