40 



NATURE 



[Afay 



Sundays, bears principally on the use of the lathe for model- 

 ling. M. Herve Mangon, having e:>tablislied a Siemens electro- 

 magnetic machine for lighting purposes at the Conservatoire, 

 sends by request snpplie.i to the several laboratories of the estab- 

 lishment. Up to the present moment it has been used only 

 by photographers. 



At the adjourned ordinary meeting of the Sanitary Institute, 

 to be held at 9, Conduit Street, on Wednesday, May 18, at 

 S p.m., the discussion will be continued upon the address 

 delivered by Dr. Richardson, F.R.S., Chairman of Council — 

 " Suggestions for tlie Management of Cases of Small Pox, and 

 of other Infectious Diseases in the Metropolis and Large Towns." 

 At the meeting of the Iron and Steel Institute last week the 

 papers were almost entirely of a purely technical or commercial 

 character. 



Mr. Charles E. Turner, Lector at the University of St. 

 Petersburg, will begin a course of five lectures at the Royal 

 Institution, on the Great Modern Writers of Russia— Pouschkin, 

 Lermontoff, Gogol, Tourgenieff and Nekrasoff— on Saturday, 

 the 2lst. 



An International Medical Congress meets at Madrid on the 

 20th inst. 



The extinction of the Brush electric light in the City last 

 week is stated to have been caused by the defective insulation 

 of the wires. 



All the large railway companies in the country have inti- 

 mated their intention of sending engines to the typical engine 

 exhibition to be held at Newcastle on the occr.sion of the 

 Stephenson centenary. 



The annual meeting of the U.S. Society for the Promotion 

 of Agricultural Science will be held at Cincinnati on Tues- 

 day, August 16, the day preceding tlie session of the American 

 "Association for the Advancement of Science. 



The fifth and concluding course of Cantor Lec.ures for the 

 present session at the Society of Arts will be by Mr. R. 

 Brudenell Carter, on the subject of "Colour Blindness, and its 

 Influence on Various Industries." The course con!i^ts of tliree 

 lectures, the first of which will be delivered upon Monday next, 

 the l6th inst. This lecture will deal generally with the subject. 

 The second lecture will treat of methods of testing for colour 

 blindne.-s, the prevalence of the affection, mistakes of the colour 

 blind, and methods of endeavouring to 'counteract the defect. 

 The subject of the third lecture is specially the industries chiefly 

 affected by colour blindness. In it an account will be given of 

 recent legislation on the subject in America, and the necessity for 

 'it in this country. 



Masson of Paris has issued a third series of Prof. Paul 

 Bert's " Revues scienlifiques," jublished in the Republiqnc 

 fraiicaise. 



The Annual Report of the Belfast Naturahsts' Field Club for 

 1879-80 tells of its continued prosperity, and contains an account 

 of the various excursions made during last summer. Appended 

 are "A List of the Post-Tertiary Foraminifera of the North- 



■ East of Ireland," by Joseph Wright, F.G.S., and "A List of 

 .the MoUusca of the Boulder Clay of the North-East of Ireland," 



■ by S. A. Stewart. 



The Birmingham Natural History Society has issued a Report 

 ami Transactions for iSSo, which in quantity and quality does its 

 member, great credit. There is an interesting address by the 

 prisident, Mr. W. Southall, and a number of natural history 

 pipers, some by outsiders, and one or two on subjects connected 

 with local natural history. The Society is now housed in the 

 ^lason College. 



In comjiliance \(ith the provisions of a recent decree, the 

 system of Algerian telegraphy has been rattaclie to the French 



administration, and is governed from Paris. The head of the 

 Algerian service has been appointed director at Lyons. 



The annual conversazione given by the President and Council 

 of the Royal Society was hold on Wednesday last week. It was 

 well attended, and there were numerous scientific and artistic 

 novelties on view. 



Mr. E. im Thurm is writing on Aspects of Plant Life in 

 British Guiana, in the Gardeners' Chronicle. 



The additions to the Zoological Society's Gardens during the 

 past week include a Black-faced Spider Monkey (Aides ater) 

 from Eastern Peru, a Collared Peccary {Dicotyles tajapt) from 

 South America, presented by Mr. E. H. Dance ; a Roseate 

 Cockatoo (Cacatua roseicapilia] from Australia, presented by Sir 

 Charles C. Smith, Bart. ; a Swift {Cypielus apiis), European, 

 presented by Mr. H. H. Johnston; a Common yi^er (Vipera 

 herns'), British, presented by Mr. John Poyer Poyer. 



OUR ASTRONOMICAL COLUMN 



The Comet of 1812. — Under certain suppositions as regards 

 the epoch of perihelion passage of this comet, the I'eturn of which 

 may now be expected, it will be nece-sary to search for it on a 

 particular date, upon the assumption that it has yet a considerable 

 orbital angle to describe before arriving in perihelion, because 

 the geocentric position corresponding to a small orbital angle will 

 place the comet too near to the sun's position to allow of obser- 

 vations. If we employ the elliptical elements dediiced by Mr. 

 W. E. Plammer from a new reduction and discussion of several 

 of the most reliable series of (jbservations in 1S12, -we find the 

 following values of the comet's heliocentric equatorial co- 

 ordinates and of the radius vector for intervals of 100 days to 60 

 days before perihelion passage ; the co-ordinates are referred to 

 the equinox of iSSl'o. 



Time from Log. radius- 



perihelion. ,x. y. z, vector. 



- 100 days ... -f 0-5619 ... -0-S939 ... -H'6649 ... o'26S3 



- 90 ,, ... +0-5478... -0-4432 .. -(-1-5725 ... 0-2363 



- So ,, ... -f 0-5305 ... -0-2904... -f 1-4712 ... 0-2016 



- 70 ,, ... -fo-5093 ... -0-1357... +1-3592...0-1637 



- 60 ,, ... +0-4832 ... +00209 ... +I'2337 ... 0-I222 

 Combining these co-ordinates with the X, Y, Z of the Nauticai. 

 Almanac for May 27-5 and June 26-5, days of new moon in the 

 present year, we get the following results : — 



For May 27-5 

 R.A. Decl. Distance fron: 



These places will define the region of the sky where the comet 

 should be sought, and telescopes of good optical capacity will be 

 needed. When Pons discovered the comet on July 20, 1812, 

 the theoretical intensity of light was 0-18. 



The mean motion in 1812 not being ascertainable within very 

 narrow limits, no attempt, so far as we know, has b.;en made to 

 determine the effect of perturbation in the present revolution, 

 and we have therefore to be content with the method of careful 

 sweeping over the region of the sky, on which the orbit may be 

 projected at any time. Sir George Airy's orbit-sweeper, it is 

 true, -.vould limit the extent of sky-ground to be ex.unined, but 

 we suspect the only instrument of sufficient power yet mounted 

 upon his principle is that at the Imperial Observatory at Strass- 

 burg, where it is not to be doubted that it will be put in active 

 operation by Prjf. Wiiinecke. We may remind the reader that 



