434 The Royal Society Soiree. 
card behind it. No opportunity, on account of the direc-. 
tion of the street and the wall of the court, was afforded of 
testing the light at any greater distance. The light pro- 
duced by Mr. Wilde’s machine may be compared with that: 
derivable from a thousand Grove cells with platina of | 
6 inches by 3 inches; and it absorbs from 8 to 10 horse- 
power out of the engine. | 
Electricity held sway in other rooms. Mr. Siemens oc- 
cupied the Linnzan Room, and Professor Wheatstone the 
Library. 
Amongst the many valuable philosophical instruments 
exhibited, the most remarkable was the new spectroscope 
invented by Mr. Browning for Lord Rosse’s telescope at 
Parsonstown. Space does not permit us to enter into 
descriptions of this instrument, and the many other remark- 
able objects of interest shown at this memorable Soirée.. 
We must therefore content ourselves with simply enume- 
rating the following, as most worthy of notice :—Specimens 
of the Atlantic telegraph cable, with the grapnel shown in 
action, as at the bow of the Great Eastern, by Sir Samuel 
Canning. Silvered glass reflector of 124 inches diameter, 
and two drawings of Mars taken during the recent opposi- 
tion, by Mr. J. Browning. Telegraph thermometer and 
cryptographs, and automatic telegraph, by Professor Wheat- 
stone, F.R.S. Collection of recent and fossil otolites, or 
ear-bones of fishes, by Mr. E. T. Higgins. Lithographs by 
Mr. De Wilde of new British madreporia, by Dr. P. M. Dun- 
can. Some excellent instruments by Messrs. Cooke and 
Sons, and by Mr. Troughton and Simms, for the great tri- 
gonometrical survey of India, by Lieut.-Colonel Strange, 
F.R.S. Professor Smith’s binocular eye-piece for micro- 
scopes, by Mr. Ladd, Combined electrometer and electro- 
dynamometer, for determining the ratio of the electrostatic 
and electromagnetic units by means of equilibrium between 
an electrostatic attraction and electromagnetic repulsion, 
and a real image stereoscope, with illustrations of geometry 
of three dimensions, by J. Clerk Maxwell, F.R.S. Ther- 
mograph of the new Kent pattern, by B. Stewart, F.R.S. 
Robinson’s anemometer, on a new pattern, and one of the 
‘mural standards constructed for the British Association, 
by Mr. Casella Further most illustrative specimens of 
Eozoon Canadense, with photograph, including a spe- 
cimen from the limestone, by Sir W. E. Logan, F.RS. 
-Specimens of salts of the metal Thallium, by Messrs. 
Hopkin and Williams. Fossil bones of Dinornis, by Pro- 
