192 KECORD OF SCIENCE FOR 1887 AND 1888. 



A device adopted at Greenwich in the observations of occultations 

 during^ the eclii)se of the moon on January 28, 1888, seems worthy of 

 record. The eyepiece of the telescope was mounted eccentrically from 

 the axis at the distance of the moon's radius, so that, without disturb- 

 ing the ])Osition of the telescope, any point of the limb could be 

 brought into the center of the field. For setting the position-circles 

 rapidly in the dark, card-board circles, with notches cut at important 

 points whi(;h could be felt with the fingers, were used; and in another 

 case luminous paint was found to work admirably for indicating the 

 figures. 



In the report of the Melbourne Observatory Mr. Ellery describes a 

 form of micrometer used successfully on the great reflector for making 

 sketches of nebuhe. It consists of a number of silver threads crossing 

 at right angles, and rendered visible at will by means of an electric 

 current. 



M. Perigaud has found that the essential condition in the artificial 

 horizon oevised by Gautier for the meridian work of the l^aris Observa- 

 tory is that the mercury should form an extremely thin covering upon 

 the bottom of the containing vessel. For the inn( r basin used in Gau- 

 tier's apparatus he has substituted a ])late of such diameter as to leave 

 a space of 5 millimeters between its edge and the side of the outer ves- 

 sel, and the plate being carefully levelled, it is possible to flow over it a 

 mere film of mercury, which will give sharp images under most adverse 

 circumstances. • " 



It may not be out of place here to call attention to the suggestion 

 made by Brashear and others in regard to standard dimensions in as- 

 tronomical and physical instruments. The great convenience which 

 would result from having the fittings of telescopes, eye pieces, draw 

 tubes, etc., interchangeable can hardly be over-estimated, 



MISCELLANEOUS. 



The Lalande prize of the Paris Academy in 1S87 was awarded to Dr. 

 Duuer, of the Lund Observatory, Sweden, for his double star work ami 

 his researches on stellar spectra; the Valz prize to Perigaud for his 

 valuable investigations of the meridian instruments of the Paris Ob- 

 servatory and other important astronomical work. The Janssen prize 

 for progress in astronotnical physics, awarded this year for the first 

 time, was decreed to the late Dr. Kirchhofl"; the Arago medal, also 

 awarded for the first time, to Bischoffsheim the founder of the Nice 

 Observatory; and the La Caze physical prize to Paul and Prosper 

 Henry for their work in astronomical photogmphy. The Rumford 

 medal of the Royal Society was presented to Professor Tacchini, for 

 his investigations on the physics of the sun, November 30, 1888. 



In 1888 the Lalande prize was awarded to Bossert for his extensive 

 and valuable astronomical computations; the Valz prize, to Prof. E. C. 

 Pickering for photometric work : the Janssen prize, to Dr. Huggins for 



