SCIENCE-GOSSIF. 



249 



the planetary nebula N.G.C. (New General Cata- 

 logue) 3918. Admirable pictures appear in the 

 " Illustrated London News " of November 23rd, 

 1901 , reproducing the photograph of the spiral nebu- 

 losity around Nova Persei taken by Mr. W. Ritchey, 

 at Yerkes Observatory, together with an explana- 

 tory sketch which shows details appearing in the 

 original negative, but which are barely visible in 

 the prints. This nebulosity must not be confounded 

 with the optical aureola. It is amid this nebu- 

 losity that the rapid motion has been observed at 

 Lick Observatory. The greatest proper motion of 

 any star hitherto observed amounts to only 8'7" 

 per annum, whilst the motion of these nebular 

 nuclei is equal to 11'. This, were the nebula at 

 the distance of 61 Cygni, which has a parallax of 

 0'39", would mean 55,200 miles per second, or over 

 five radii of the earth's orbit in one day. 



Minor Planets. — During the month ending- 

 November 15th eight of these little bodies were 

 discovered by Professor Max Wolf and his fellow 

 workers at the Heidelberg Observatory ; and a ninth 



CONDUCTED BY P. SHILLINGTON SCALES, F.R.M.S. 



Royal Microscopical Society, November 20th. 

 — Wm. Carruthers, Esq., F.R.S., President, in the 

 chair. Four microscopes of great interest were 

 presented to the Society. Descriptions of three 

 of these, prepared by Mr. Nelson, were read. Re- 

 garding one made by Powell & Lealand, in 1848, 

 Mr. Nelson writes: " This form was the first instance 

 in which the microscope was hung in a tripod, and 

 it was also the first where the fine adjustment 

 moved a nose-piece by means of a lever inside a 



Track on Photo : Plate with Two Minor Planets 



was found by Luther at Diisseldorf. By the 

 kindness of Professor Max Wolf, of Heidelberg, 

 we are able to reproduce the photograph taken 

 on November 4th, aftejr an exposure of 2 hours 

 with the 16-inch Bruce telescope. This shows 

 the trail on the right of one, the new 13'5 magni- 

 tude planet, as yet designated H.C., and also the 

 trail of another faint planet, No. 380, discovered 

 in 1894. The position of H.C. was R.A. 2h. 6'3 m., 

 Dec. N. 3° 27'. The plate is enlarged three-and-a- 

 half times. 



Professor J. E. Keeler. — The Governing Com- 

 mittee of the Allegheny Observatory have resolved 

 to erect a 30-inch reflector as a memorial to the 

 late Professor J. E. Keeler, who, previously to his 

 appointment to Lick Observatory, had been 

 Director of the Allegheny Observatory. It is 

 expected the instrument will cost £2,000. 



bar movement, and this specimen must have been 

 about the last microscope made with the fine ad- 

 justment screw at the side of the bar, for it was 

 in 1848 that the screw was placed vertically above 

 the lever, where it has remained ever since." Other 

 features were referred to, and Mr. Nelson charac- 

 terised it as historically an important and not very 

 common form of Powell & Lealand's microscope. 

 The next instrument described was an old one 

 made by Hugh Powell, certainly before 1841, as in 

 that year Mr. Lealand joined the firm, and his 

 name would have been coupled with that of Mr. 

 Powell. The presence of a sub-stage condenser 

 prevents it being dated earlier than 1839. An im- 

 portant feature is the stage which has an arrange- 

 ment for focussing by means of three wedges 

 moved by a micrometer screw. The stage has also 

 a transverse micrometer movement for the measure- 

 ment of objects. The third microscope was made 



