ii4 



NATURE 



[June i, 1882 



premiums annually for the best original papers sent in to the 

 Society on Telegraphic or Electrical Subjects during the Session 

 by any person not being a m.mber of the Council of the Society. 

 The 1st Premium will be called the Society's Premium, value 

 10/. ; 2nd, the Paris Electrical Exhibition Premium, value 5/. ; 

 3rd, the Fahie Premium, value 5/. The Premiums will consist 

 of books or scientific apparatus. The first Premium will be 

 awarded in 1883 for the best papers sent in between this date 

 and the end of May next. 



Dr. F. A. Fokel, of Morges, informs us that the supposed 

 lacustrine canoe referred to in Nature, vol. xxvi. p. 67, was 

 really a simple trough made out of a log, for the reception of 

 spring water. 



The additions to the Zoological Society's Gardens during the 

 past week include a Spotted Cavy (Caiogenys paca) from South 

 America, presented by Mr. V. Gibbs ; a Red Brocket (Cariaats 

 rufus i ) from Trinidad, presented by Mr. H. Sandbach ; a 

 Black-breasted Sparrow (Passer diffusus i ), a White-throated 

 Seed Eater (Critliaga albogularis) from South Africa, presented 

 by Mr. J. Abrahams ; a Horned Lizard (Phrynosoma cornutum) 

 from Texas, presented by Capt. E. C. B. Walker ; three Mid- 

 wife Toads (Alytes obstetricans), fourteen Alpine Newts (Triton 

 alpestris) from Belgium, presented by M. G. A. Boulenger ; a 

 Lesser White- nosed Monkey (Cercopithecus petaurista 9 ) from 

 West Africa, a Jackass Penguin (Sphenisats magcllaniais) from 

 the Falkland Islands, two Cape Crowned Cranes (Bahar'ua 

 chrysoptlargus) from South Africa, a Flamingo (Phanicopltrus 

 antiquortim) from North Africa, two Bernicle Geese (Bernicla 

 leiuopsis), two White-fronted Geese (Anser albifrms), a Ruddy 

 Sheldrake (Tadorna rutila), a Herring Gull (Lams argentatus), 

 European, a Bordeaux Snake (Corondla girondicd), South 

 European, deposited; a Koala (Phascolarctos cinereus) from 

 Australia, two Javan Peafowls (Pavo spicifer i 9 ) from Java, 

 purchased ; a Collared Fruit Bat (Cynonycteris collaris), born in 

 the Gardens. 



OUR ASTRONOMICAL COLUMN 

 The Comet. — The following orbit of the present comet has 

 been calculated by Mr. Hind, from observations at Harvard 

 College, U.S., on March 19, Josephstadt (Vienna) on April 19, 

 and one by Prof. Millosevich, at the Collegio Romano, Rome, 

 on May 21 ; parallax and aberration were taken into account : — 

 Perihelion passage, June IC52442 Greenwich M.T. 



Longitude of perihelion 53 55 l8'0\ From M. Eq., 



,, ascending node... 204 53 56-9 ( lS82'o. 



Inclination 73 46 39'8 



Log. of perihelion distance ... 8782864 

 Motion — direct. 

 From these elements we find the positions near perihelion 

 pas-age thus — 



Distance from Sun's 



centre. Intensity 



R.A. DecL InR.A. InDecl. of Light, 



d. h. „ , 



June 10 0...74 58-4... +23 419... -3 33. ..+0 40... 82-6 



10 6 ..75 50-8... +22 34-5... -2 56... -O 29 ..104-5 



10 18 ...78 0"2... +20 292. ..-I 18... -2 36. ..I052 



11 0...79 i6 - i... + i9 404... -o 17... - 3 26... 87^6 



The intensity of light on May 21 has been taken as unity. 

 The comet was then judged to have the brightness of a star of 

 5 -6m. On May 18 Mr. G. Knott estimated it a little higher than 

 6'o, which fairly accords. Whence theory would raise it to over 

 an average first magnitude at perihelion. With due precautions 

 which will occur to most observers who have large refractors, it 

 is now seen to be by no means improbable that the comet may 

 be observed in full daylight, on June 10 and II. Still it may 

 be well te remark that as compared with the first comet of 1S47, 

 observed at noon, close to the sun, on March 30, by Mr. Hind, 

 with a 7-inch refractor, stopped down to about 3 inches, the 

 theoretical intensity of light at perihelion is not quite half as 

 great ; thus calling the brightness unity when the cornet was first 



glimpsed with the naked eye, the brightness of the present comet 

 at perihelion will be 186, while that of the comet of 1847 was 

 40S. 



By the above orbit the comet traverses the plane of the ecliptic 

 at the ascending node 0^038 within the earth's track. 



Double Stars. — No. 6 of "Publications of the Cincinnati 

 Observatory " has been issued. It contains micrometrical mea- 

 sures of double stars made with the 1 1 -inch refractor in 1879-80, 

 consisting partly of observations preliminary to the formation of 

 a general catalogue of known double stars situated between the 

 equator and 30 south declination, and partly of observations of 

 objects which Mr. Burnham has found to need re-observing. 

 The cases of notable differences from previous measures are col- 

 lected in the introduction. Mr. Ormond Stone is doing excellent 

 work with his refractor, which appears to have been much im- 

 proved since the object-glass was re-figured by Messrs. Alvan 

 Clark and Son. 



The Variable Star U Geminorum.— Mr. G. Knott, 

 writing from Cuckfield on May 29, states that he had caught a 

 maximum of this apparently capricious variable on May 27 or 

 28 ; on both nights it was about 9-9 m. This, compared with 

 the previous maximum noted by the same observer on February 

 2S, gives a period of eighty-eight days. 



Prof. Schonfeld finds that a star R.A. i6h. 1301. 36s., 

 Deck - 7° 2l"o for 1855 is variable. 



A star in R.A. 19(1. 17m. 33s., Decl. -21° 32''3 for 1850, 

 must be variable to a great extent — 65 to 9'o at least. 



TEMPERA TURE REGULA TORS 

 TJEFORE proceeding to the consideration of some of the 

 means adopted for controlling temperature, more or less 

 perfectly, it will be as well 1 3 notice two instruments, because 

 although they are in really only indicators, yet the latter is 

 always referred to as a regulator. 



Hall's aerometer 1 consists of a glass bulb 4I c.i. incapacity, 

 attached to a long tube whose capacity is 1 c.i. This tube 

 is inserted into another of nearly equal length, and supp >rted on 

 a stand. The first tube admits of being sustained within the 

 second at any given height by means of a spring. The outer 

 tube is charged with mercury or water, according to circum- 

 stances, and the bulb and inner tube are arranged to contain, at 

 the normal pressure and temperature, 5 c.i. of air. Any changes, 

 therefore, in the atmospheric conditions will affect the level in 

 the inner tube, and can be allowed for accordingly. 



Doyere's regulator - (1848), which is on the same principle, 

 consists of a glass bulb, to the bottom of which a fine tube is 

 attached. This tube is bent, then carried upwards for a certain 

 distance, is then bent again to form an inverted U-tube, the 

 extremity is again bent upwards, and terminates in an open bulb. 

 The lower bulb and the quill-tube are partly filled with water, 

 the surface of which in the tube indicates by its change of 

 position the alterations in the volume of the air contained in the 

 bulb. The principle on which Fresenius' cast-iron drying-disk 

 is constructed is the same which long ago led to the use of sand- 

 baths, for it is obvious that if a large mass must be warmed 

 before the heat can reach the substance, a rapid rise in tempe- 

 rature is impossible. The number of substances which can be 

 conveniently dried at the temperature of boiling water, and the 

 number of chemical operations which require that temperature, 

 have led to the construction of every variety of wat;r-bath and 

 water-oven. With a temperature not much above the boiling 

 point of water, the increase may be obtained by using solutions 

 of various salts ; but with these the evils of bumping and crystal- 

 lisation are so great that Sprengel (1869) 3 replaced the water in a 

 water-oven by sulphuric acid having a specific gravity of rS5> 

 and for tint purpose constructed a leaden one of the following 

 description : The outside case of the double-walled air-bith is 

 a 61-inch cube, the inside a 5-inch cube. The worm, made of 

 about 30 feet of leaden piping of ^-inch diameter, is 15 inches 

 high and 4 inches wide. The coils of the worm are kept apart 

 from each other -J inch by means of solder, and the worm is 

 kept in its upright position by two iron supports soldered to the 

 sides of the air-bath. 



Laspeyres ' (1874), using the same liquid, constructed two 

 pieces of apparatus. One was a glass flask so arranged that 



■ Q. y. Sci. v 52 (181S) Faraday's manip. 375. 



= Ann. Chim, Phys. (3] xxviii. 5 (1850), Gerliardt 1,105. 



3 Journ. Ckem. Soc. xxvi. 458 (1873). « Pog?. Aim. clii. 13= (1874)- 



