452 



NATURE 



[September 8, 1892 



question in electricity, and to organize a committee who should 

 propose the subjects, examine the productions, and decide the 

 prize. The following gentlemen have consented to act as 

 members of the Committee : — J. Carpentier, President of the 

 Societe Internationale des Electriciens ; Hippolyte Fontaine ; 

 E. Hospitaller, Professor in the School of Physics and Chemistry 

 of the City of Paris ; E, Mascart, Member of the Institute ; A. 

 Potier, Member of the Institute (Examiner) ; B. Abdank- 

 Abakanowicz, Consulting Engineer (Secretary of the Com- 

 mittee). The Committee has decided that the prize should be 

 given for an investigation on one of the following subjects : — 

 (l) The heat developed by successive charges and discharges of 

 condensers under different conditions of frequency, nature of 

 dielectric, and quantity of charge. (2) It has been shown theo- 

 retically that when the two surfaces of a condenser are connected 

 by a conducting body, the condenser becomes the source of 

 alternating currents as soon as the resistance of the conducting 

 body decreases below a certain limit. The formula that permits 

 calculating the period of this oscillation has not yet been com- 

 pletely verified. This period of oscillation should be investi- 

 gated experimentally under conditions such that the exact 

 measure of resistance, capacity, and coefficients of self-induction 

 may be possible, in order to arrive at a complete and pre- 

 cise verification of this formula. (3) When a condenser made 

 with an imperfect insulating material has been charged and then 

 left to itself, the charge is gradually dissipated. The time 

 necessary for the charge to be reduced to a given fraction of its 

 initial value depends only on the nature of the insulating ma- 

 terial. It is proposed to investigate whether, as certain recent 

 theories would seem to indicate, analogous phenomena do not 

 present themselves in metallic conductors, and whether these 

 can be shown experimentally. (4) It is proposed to arrange and 

 systematize our present knowledge of the graphical solutions of 

 electrical problems, and deduce from them some general methods 

 as in graphical statics. The theses presented may be written in 

 any one of the following languages : — English, French, German, 

 Italian, Spanish, or Latin. They may be in manuscript or 

 printed. Each thesis presented must be signed by a pseudonym 

 and accompanied by a sealed envelope bearing the same pseudo- 

 nym on the outside, and with the name and address of the 

 author inside. The papers must be sent before September 15, 

 1893, to B. Abdank-Abakanowicz, Consulting Engineer, the 

 Secretary of the Committee, at 7 Rue du Louvre, Paris, who 

 will furnish any further information required. 



The additions to the Zoological Society's Gardens during the 

 past week include a Black-handed Spider Monkey {Ateles 

 geoffroyi) from Nicaragua, presented by Mr. F. Vyner ; a 

 Macaque Monkey {Macacus cynomolgus S ) from India, pre- 

 sented by Mr. Gerald E. Bridge ; a Black-shouldered Kite 

 {Elanus cceruleus) captured at sea, presented by Mr. J. Watson ; 

 a Falcated Teal {Querquedula falcata 6 ) from China, presented 

 by Mr. A. C. Moule; an American Black Snake {Coluber 

 guttata) from North America, deposited ; two Mule Deer 

 ( Cariacus macrotis ? ? ) born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 

 The Staff at the Lick Observatory. — We are 

 sorry to notice the very considerable changes that are now taking 

 place in the staff at the Lick Observatory. It seems only quite 

 recently that Prof. Keeler tendered his resignation to take over 

 the directorship of the Allegheny Observatory, but now we hear 

 that Mr. Burnham has resigned, and that Prof. Henry Crew has 

 done the same, the former having accepted a position of clerk 

 in one of the courts of Chicago, and the latter having been 

 elected to a Professorship of Physics in the North-Western 

 University at Evanstown, 111. With the loss of these men the 

 observatory will be crippled for some time ; for, although very 

 good men will be found to take their places, a thorough acquaint- 



NO. I 193, VOL. 46] 



ance with the instruments can be obtained only bv constant and 

 frequent practice. Of the remainder of the staff Mr. Barnard 

 and Mr. Schaeberle will be the only representatives of the older 

 members. What the cause of these changes is we do not 

 know, but there seem to be signs of a little friction somewhere, 

 for what is the probability that three men should sever their 

 connection with such an observatory in the space of a year- 

 assuming, of course, normal conditions? 



The Observations of Klinkerfues Reduced.— The 

 second part of the Astronomische Mittheilungen of the Royal 

 Observatory in Gottingen contains a complete reduction 

 of Klinkerfues' observations which he made in the years 1858 

 to 1863. The work has been undertaken by the Director of 

 the Gottingen Observatory, Prof Wilhelm Schur, and has been 

 printed at the expense of the Konig. Gesellschaft der Wissen- 

 schaften zu Gottingen. In the introduction Prof. Schur gives a 

 complete account of the instruments used and the methods by 

 which the observations were made. The zone included in this 

 work is that which lies between + 15° and - 15° declination. 

 The interest that is attached especially to these observations is 

 caused by the fact that Klinkerfues did not wish to adopt the 

 usual method for determining the declinations directly from the 

 readings of the vertical circles, but he used that generally known 

 as Gauss' method, in which a mirror and scale played an im- 

 portant part. The epoch to which all the places are referred is 

 that of i860, and a table is also added by which the yearly 

 precession in right ascension and declination can be easily 

 determined. 



Photographs of Solar Phenomena. — To the August 

 number of Astronomy and Astro-Physics are contributed some 

 striking pictures that represent some of the latest advances made 

 by the application of the photographic plate to the telescope. 

 These photographs were taken by Prof. G. E. Hale, of the 

 Kenwood Astro-Physical Observatory, with the new spectro- 

 heliograph, a description of which instrument will be found in 

 the May number of the same Journal. The first photograph 

 displays the spots and faculae on the solar surface on May 21 

 last : a single glance at it will show us that we shall have to 

 change very considerably our present ideas as to their extent, for 

 instead of equalling the spots in area they exceed them so much 

 as to place them relatively in entire insignificance. Another 

 point that is at first noticed from the same photograph is the 

 paucity of the faculae at the limb with respect 10 the more 

 central part of the disc, but this is, as we are told, only a fault 

 in the process of reproduction, for in the original negatives the 

 faculse " are equally well shown on all parts of the solar surface." 

 Another photograph of interest is that of the chromosphere and 

 prominences taken on the same day ; this was obtained by 

 cutting off the light issuing from the solar disc by means of a 

 metallic diaphragm ; it resembles very strikingly a short-exposed 

 photograph of the eclipsed sun, as the prominences on it as 

 distinctly visible, while the presence of streamers and rifts is 

 lacking. Since these photographs were taken, Prof. Hale has 

 been able, by making two exposures on the same plate, to 

 produce pictures each of which displays all the solar phenomena. 

 For the first exposure he employed the metallic diaphragm, 

 allowing the slits which move across it to travel with the velo- 

 city required for the prominences ; for the second exposure the 

 diaphragm was removed, and the rate of movement of the slits 

 was this time very much increased. 



A Meteorite. — In the American Journal of Science for 

 August, Mr. H. L. Preston gives an account of the finding of 

 a meteorite in Kenton County, eight miles south of Indepen- 

 dence. In the year 1889 during the cleaning out of a spring, 

 something very hard was struck which from the sound was 

 thought to be metal. It was entangled among the roots of an ash 

 tree three or four feet down in the ground, and was not removed 

 from the spot until August 1890, when it was placed in a shed, 

 and more recently bought for the Ward collection of meteorites. 

 The measurements along its greatest diameters were 21 x 14x8 

 inches, and it weighed 359^ pounds. Its surface was covered 

 with numerous but mostly shallow pittings, but was entirely free 

 from crust. An analysis showed that it contained iron to the 

 amount of 91-59 per cent., nickel 7-65, cobalt o'84, carbon o'i2, 

 with traces of copper and sulphur. 



Mounting of Objectives. — A novel but very useiul way of 

 mounting objectives is that adopted by Prof. Hale, who has 



