268 



NA TURE 



\Feb. 3, 1876 



The Science and Art class to which you refer has recently been 

 orj;anisec1, and is said to be answering very well. 



There is, however, a possibility that this state of things will be 

 soon partly altered, for rumours are afloat that our excellent 

 member, Mr. Brassey, has offered to provide a suitable building 

 in which all the local societies will have apartments, but no par- 

 ticulars are yet known. 



Hastings, Jan. 28 Ai.EX. E. Murray 



P.S. — Since writing the above I remember that I have omitted 

 the Athenaeum, but as this is mainly a debating society it has 

 little to do with the advance of science. 



OUR ASTRONOMICAL COLUMN 

 The Total Solar Eclipse of 1876, Sept. 17-18. 

 —The track of totality in this eclipse is wholly upon 

 the Pacific Ocean, and in such course that only two or 

 three small islands or reefs appear to be situate near the 

 central line. Using the Nautical Almanac elements, 

 which are almost identical with those of the American 

 Ephemeris, wherein the moon's place is derived from 

 Peirce's Tables, St. Matthias Island, west of Admiralty 

 Islands off the north-east coast of New Guinea, is tra- 

 versed by the central track of the shadow, with the sun 

 at an altitude of 5° at 6h. i6m. a.m. on the iSth local 

 time. Thence skirting Ellice Islands it passes between 

 the Fiji's and the Samoan or Navigator group to Savage 

 Island, in 170° west of Greenwich, latitude 19° south, 

 which is apparently the only spot where totality may be 

 witnessed under anything like favourable conditions, and 

 even here the duration of totality is less than one minute. 

 The after course of the central line does not encounter 

 any land. 



In the northern of the two large islands of the Fiji 

 group (Vanua Levu) 179° east, a partial eclipse will occur 

 commencing at 7h. 47m. AM. local time 44° from the 

 sun's north point towards the west for direct image, and 

 ending at loh. 16m., magnitude o*86. In the larger 

 island of the Navigator group, Savaii, of the Admiralty 

 Chart, there will also be a partial eclipse, though nearly 

 approaching totality ; eclipse begins 8h. 23m. A.M. at 53° 

 from the sun's north point towards the west, and ends at 

 iih. 2m., magnitude 0*97. 



Assuming the north point of Savage Island to be in 

 169° 48' W., with 18° 55' south latitude, a direct calcu- 

 lation gives a total eclipse commencing at loh. 8m. 6s. 

 A.M. local mean time, and continuing 57 seconds with the 

 sun at an altitude of 58° ; the first contact of the moon 

 with the sun's limb at 8h. 48m. a.m., 49° from his north 

 point towards west for direct image, and the end of the 

 eclipse at i ih. 29m. 



In New Zealand the eclipse attains a magnitude of 

 about o*5 at Auckland, greatest phase at Qh. i8m. A.M. ; 

 towards the extremity of the southern island about Otago, 

 one-third of the sun's diameter will be obscured about 

 9h. 12m. local time. A partial eclipse between similar 

 limits will be visible on the east coast of Australia and in 

 Van Diemen's Land. 



Minor Planets. — The long period of revolution 

 assigned to No. 153, Htlda,hy the early calculations has 

 been confirmed by a new determination of the elements 

 by Herr Kiihnert, of Vienna, upon more than eight weeks' 

 observations. The orbit is as follows : — 



Mean Longitude, 1875, Dec. 19, at Berlin ) „, 



noon ... ) 34 5 7 



Longitude of perihelion 285° i'-6 



„ „ ascending node ... 228° 20' -5 



Inclination to ecliptic 7° 50' "9 



Excentricity 016311 



Mean diurnal motion 45l"9l 



Semi-axis major 3'9504 



Hence the period of sidereal revolution is 2,868 days, or 

 7*85 years. — For No. 158 detected at Berlin on Jan. 4, 

 Dr. Maywald, who has been so long occupied in computa- 

 tions connected with the minor planets, has proposed the 

 name " Koronis." — No. 155, discovered by Palisa at Pola 



on Nov. 8, has so far been observed only on four nights, 

 and these observations being at intervals which render 

 them unavailable for calculation of elliptical elements, it 

 appears not unlikely that it will be lost, as are already 

 several minor planets similarly circumstanced, unless an 

 effort be made to recover it with the aid of circular 

 elements in the next period of absence of moonlight, and 

 with some one of the larger telescopes ; it was not 

 brighter than a star of the twelfth magnitude at dis- 

 covery, and must now be considerably fainter. — The 

 period of revolution of No. 150 by seven weeks' observa- 

 tions is 1,879^ days. 



M. Paul Henry, of the Observatory of Paris, announces 

 his discovery of No. 159 on Jan. 26. 



The Second Comet of 1702.— A complete reduction 

 and discussion of the observations of this comet, taken 

 at Rome by Bianchini and Maraldi, docs not afford indi- 

 cations of elliptical motion, as might be surmised to exist 

 from the small inclination of the orbit to the ecliptic and 

 the direct movement. In fact, these observations appear 

 to be by no means precise, and the differences from cal- 

 culation ijiter se are too irregular to afford any hope of 

 sensibly improving upon the orbit given by Burckhardt. 

 Considering that the differences of right ascension be- 

 tween the comet and comparison stars were taken by 

 means of clocks, and the differences of declination 

 measured by a micrometer scale, the arc value of which 

 was determined by observation of the sun's diameter, 

 rather better places might have been looked for. The 

 following are the errors given by Burckhardt's orbit, as 

 compared with the newly reduced positions in which 

 aberration and parallax have been taken into account : — 

 1702, April 20 A A. cos. ;8 ... + 7''2 Ay8 ... - i'-2 

 ,, „ 21 ,, ... -1-6 ,, ... - 6-1 



„ „ 26 „ ... -1-4 „ ... - I -8 



M „ 27 „ ... - 3-5 „ ... +2-4 



„ May 2 „ ... -1- 9-1 „ ... - 3-1 



„ „ 4 >» ••• - 7 '6 „ ... -3-6 



The comet was at its least distance from the earth on 

 the night of April 19, when it approached our globe 

 within 0*0438 of the earth's mean distance from the sun. 



PROF. TYNDALL ON GERMS* 

 T N further illustration of the dangers incurred in this 

 ■»■ field of inquiry the author refers to the excellent 

 paper of Dr. Roberts on Biogenesis, in the " Philosophical 

 Transactions" for 1874. Dr. Roberts fills the bulb of 

 an ordinary pipette to about two-thirds of its capacity 

 with the infusion to be examined. In the neck of the 

 pipette he places a plug of dry cotton-wool. He then 

 hermetically seals the neck and dips the bulb into boil- 

 ing water or hot oil, where he permits it to remain for 

 the requisite time. Here we have no disturbance from 

 ebullition, and no loss by evaporation. The bulb is re- 

 moved from the hot water and permitted to cool. The 

 sealed end of the neck is then filed off, the cotton-wool 

 alone interposing between the infusion and the atmo- 

 sphere. 



The arrangement is beautiful, but it has one weak 

 point. Cotton-wool free from germs is not to be found, 

 and the plug employed by Dr. Roberts infallibly contained 

 them. In the gentle movement of the air to and fro as 

 the temperature changed, or by any shock, jar, or motion 

 to which the pipette might be subjected, we have cer- 

 tainly a cause sufficient to detach a germ now and then 

 from the cotton-wool which would fall into the infusion 

 and produce its effect. Probably, also, condensation 

 occurred at times in the neck of the pipette ; the water 

 of condensation carrying back from the cotLon-wool the 

 seeds of life. The fact of fertilisation being so rare as Dr. 

 Roberts found it to be is a proof of the care with which 



* On the Optical Deportment of the Atmosphere in reference to the Phe- 

 nomena of Putrefaction arid Infection. Abstract of a paper read before 

 the Royal Society, January 13th, by Prof. Tyndall, F.R.S. (Communicated 

 by xhe author.) Continued from p. 254. 



