4G1 Proceedings of Learned Societies. 



the occasion, and the collection of objects was very good. The 

 principal novelties were an opthalmoscope, by which the vessels in 

 the interior of a rabbit's eye were distinctly seen ; a now aneroid, by 

 Mr. Browning ; and a beantiful diffraction apparatus, by Messrs. 

 Home and Thornthwaite. The two last deserve a much longer 

 notice than we can give them in this place. The aneroid, which 

 Ave hope to describe fully another time, is a stationary instrument 

 of extreme delicacy, enabling small oscillations to be read off on a 

 large scale, and admirably adapted for noting the exact progress of 

 atmospheric waves during a storm. 



Me. De la Rue's Astronomical Soiree. — On Saturday, June 4, 

 Mr. Warren De la Rue, the President of the Royal Astronomical 

 Society, held a reception at "Willis's Rooms, which was attended by 

 a very numerous and distinguished company. The arrangements 

 were made with great liberality and good taste, and a variety of 

 important and interesting objects were brought together. Mr. 

 Nasmyth exhibited some large and wonderful drawings of lunar 

 craters ; Earl Rosse "sent sketches of nebulas, and the walls were 

 adorned with some singularly beautiful landscapes of Turner. 

 Steinheil sent a Gauss object-glass upon the pattern mentioned in 

 a former number of this journal, and Merz sent a 10-inch object 

 glass ; Cooke and Sons showed some fine telescopes, and a new 

 arrangement for obtaining a dark field illumination ; Messrs. 

 Troughton and Sons exhibited instruments for the Indian Survey, 

 among: which was an enormous theodolite in aluminium bronze. 

 Mr. Browning's new aneroid attracted great attention, and he also 

 exhibited some splendid prisms, one on a large scale, being con- 

 structed of quartz, and made for Mr. Gassiott, who was fortunate 

 in securing a crystal of rare dimensions and unusual freedom from 

 optical defects. Messrs. Home and Thornthwaite, in addition to 

 their diffraction apparatus, for which Mr. Bridges designed the 

 figures, exhibited a new form of polariscope capable of showing a 

 much wider range of effects than the usual patterns allow to bo 

 seen, and in a manner that commanded universal admiration. Mr. 

 De la Rue exhibited a complete collection of his astronomical 

 photographs. Messrs. Powell and Lealand, Eloss, and Smith and 

 Beck brought their microscopes, the latter showing the pupa of 

 (lie lieu and the Acarus Crossii. There wore also specimens of the 

 long focus telescopes that preceded the achromafics, and numerous 

 instruments <>f the most modern designs. Mr. Ladd exhibited some 

 Que effects witli vacuum tubes. 



