230 



NATURE 



[January 6, 1898 



sound. They do not vary as time goes on. The colours are 

 scarcely ever the same in two individuals. This is very clearly 

 shown in two coloured diagrams which accompany Dr. Colman's 

 paper. The first diagram shows the tint excited by the spoken 

 vowel sounds in twenty-one individuals, while the second shews 

 the tints of the colour sensations excited by the letters of the 

 alphabet in seven individuals. Dr. Colman does not, however, 

 give the colour sensations excited by numbers. The writer has 

 tested a boy at intervals within the past four years, and has found 

 that each numeral is associated with a colour as follows : — i, 

 black ; 2, white ; 3, yellow ; 4, red ; 5, green ; 6, grey ; 7, 

 mauve ; 8, light grey ; 9, brown ; o, black. These associated 

 colours have remained the same throughout the period. 



A NEW monthly journal of mechanics and electricity for 

 amateurs and students has just made its appearance under the 

 title of The Model Engineer. The periodical is intended par- 

 ticularly for amateurs who take up mechanical or electrical work 

 as a hobby. 



The additions to the Zoological Society's Gardens during the 

 past week include a Sooty Mangabey ( Cercocebiis fidiginosus) 

 from West Africa, presented by Mrs. R. H. Padbury ; a Suri- 

 cate {Swicata tetradactyla) from South Africa, presented by 

 Mrs. Soames ; a Spectacled Bear ( Ursiis ornattis, i ) from 

 Colombia, a Spotted Cavy {Ccclogenys paca) from South 

 America, presented by Mr. William Crosley ; three Brown 

 Capuchins {Cebiis fatiiellus), a Blue and Yellow Macaw i^Ara 

 araiauna), a Red and Yellow Macaw {Ara chloropterd) from 

 South America, deposited ; a Naked-throated Bell-Bird {Chas- 

 morhynchtts midicoUis) from Brazil, two Noisy Pittas {Pitta 

 strepitans) from Australia, purchased. 



OUR ASTRONOMICAL COLUMN. 



Winnecke's Comet. — As announced in this column a fort- 

 night ago, Winnecke's periodic comet is shortly due at peri- 

 helion, and therefore might be expected to be picked up at any 

 time. Such has been the case, for Prof. Perrine telegraphs 

 from the Lick Observatory that it was found on January i, 

 being only feebly visible. Its position then was R. A. 

 I5h. 19m. 42 'Ss., Decl. -3° 58' 34" S. 



Arrival of Eclipse Parties at Bombay. — Reuter's 

 correspondent at Bombay states that Mr. E. W. Maunder, Mr. 

 C. Thwaites, and the Rev. J. M. Bacon, with the parties under 

 their direction sent by the British Astronomical Association for 

 the observation of the total solar eclipse on the 22nd inst., have 

 arrived there. The different observing stations will be as fol- 

 lows : — Mr. Maunder and Mr. Thwaites will be stationed at 

 Talni, on the (}reat Indian Peninsula Railway, between 

 Amraoti and Nagpur ; the Rev. J. M. Bacon at Baxar. The 

 Astronomer Royal and Prof. H. H. Turner, forming one of the 

 official parties sent out by the joint committee of the Royal 

 Society and the Royal Astronomical Society, will be stationed 

 at Sahdol, between Katni and Bilaspur. The observing party 

 from the Government Observatory at Madras, under the direc- 

 tion of Prof. Michie Smith, will be at Indapur. 



Mont Blanc Observatory. — The closing of the year brings 

 to hand the reports from many observatories, and not the least 

 interesting is that by M. J. Janssen, in Coviptes reiidus No. 24, 

 *' On the work done in 1897 at the Mont Blanc Observatory." 



During 1897 the principal work has been the determination 

 of the quantity of heat received by the earth from the sun, or 

 the solar-constant, as it is called. 



The meteorological conditions have not been very favour- 

 able, and M. Janssen was compelled to direct observations and 

 expeditions from Chamonix, only reaching there with difficulty, 

 having seriously injured his left leg, which made an ascent of 

 Mont Blanc quite impossible for him. The observations were, 

 therefore, made by M. Hansky — first at Brevent, again at the 

 Grands Mulcts, and finally at the summit of Mont Blanc, at 

 the observatory. 



From these observations a Wi2r-f(?«j/'fl«/ of nearly 3*4 calories 

 has been deduced ; that is to say, a value notably higher than 



NO. 1 47 1, VOL. 57] 



that obtained before. This, M. Janssen thinks, will be still 

 further increased, for the more deeply the question is studied 

 the more one ascertains the complexity of the elements which 

 enter into it. For instance, of the radiations which strike the 

 earth, it is those having wave-lengths of large and small periods 

 that undergo the greatest absorption in the atmosphere ; those 

 with a mean wave-length corresponding to the most luminous 

 part of the spectrum are propagated with the least relative loss. 

 As a result of this, if the transmission of heat in a zenithal 

 direction be deduced from observations made through a great 

 thickness of the atmosphere, it will give a value much too high, 

 and hence one much too small for the solar radiations outside 

 the limits of our atmosphere, which value is the solar-constant. 

 Again, the presence of water vapour and dust particles, whether 

 of snow or other matter, all give rise to disturbing effects 

 which influence the results. To obtain precise indications of 

 water vapour the spectroscope has been used, and for the dust 

 particles and snow clouds M. Cornu's form of polariscope has 

 been employed with success. 



From these results it can be seen that it is desirable the 

 observations should be made with as little atmosphere inter- 

 vening as possible ; that is, at high altitudes — in balloons even, 

 if sufficiently precise instruments could be used in these regions 

 of the atmosphere. Nevertheless, if stations such as that of 

 Mont Blanc do not offer comparable altitudes with those which 

 balloons can reach, in return they permit the use of instruments 

 more delicate and precise, giving trustworthy results. 



Photography of Unseen Moving Celestial Bodies. — 

 Quite recently Prof. Barnard showed in Astr. Nach., 3453, how 

 it might be possible to photograph an " unseen moving but 

 known celestial body," as, for example, unseen comets, or the 

 swarm of meteorites giving rise to the November shower. The 

 method, it may be remembered, was to watch with a guiding tele- 

 scope and keep an adjacent star on cross wires moving in the 

 correct position angle at the proper rate, the movement to be 

 produced by an arrangement of watch-work. In Astr. JSlach., 

 3467, Herr Josef Jan Fric, of Prague, gives an account of a 

 somewhat similar method in which the photographic plate or 

 object glass is moved in the requisite direction. The holder is 

 driven by a fine screw, which derives its motion from the inter- 

 mittent action of a ratchet wheel moved by a " powel," which 

 in turn is actuated at will by an electro-magnet. The length of 

 stroke can easily be altered so as to give any varying motion 

 which may be 'necessary, but of course, in consequence of the 

 discontinuity of the movement produced in this way, the change 

 in the position of the plate must be so small as not to interfere 

 with the perfectness of the image photographed. 



Astronomical Annuals. — Perhaps the most useful annuals 

 for use, either in a well-established observatory or by amateurs, 

 are : the Companion to the Observatory and the Anmiaire Asiro- 

 nomiqiie et Aleteorologique; and if these two could be compounded 

 together, they would form a most desirable and complete com- 

 pendium of astronomical data. The former confines itself chiefly 

 to tabular matter giving data for finding the planets and their 

 satellites with their respective phenomena, occultations, and 

 eclipses. In addition to these, and perhaps the most important 

 section, as it is not readily found elsewhere, is the ephemeris for 

 physical observations of the sun, mean places, and maxima and 

 minima of variable stars of all periods, and also the radiant 

 points of the principal meteor showers of the year. 



The latter publication, by M. Camille Flammarion, is in its 

 thirty-fourth year, and while treating of astronomical events in a 

 popular way, it gives numerous diagrams, and has many inter- 

 esting features. The calendar, detailing observations to be made 

 for each day, has proved itself most useful, as also have the 

 charts of the positions of the planets. 



PHOTOGRAPHIC MEASUREMENT OF 

 HORSES AND OTHER ANIMALS. 



T VALUABLE horses are habitually photographed by profes- 

 sionals and amateurs, and beautiful portraits of them 

 appear in newspapers ; notably in Racing, in the Horseman 

 of the U.S.A., in Le Sport Illustre, and in other similar 

 periodicals. I am informed that in shows of pedigree stock 

 it is frequently required that the prize-winners should be photo- 

 graphed, it being of obvious importance that the appearance 

 of the progenitors of animals should be known before selec- 

 tions are made for pairing. It seems, then, that if photo- 



