February 2, 1893] 



NATURE 



317. 



As this is the first occasion on which such a peculiarity has 

 been recorded or figured, I prefer to leave all speculation as to 

 the cause out of the question. We need a good deal more 

 research before we can deal satisfactorily with the biological 

 problems involved in such appearances. As a help towards 

 this, I bring together here a list of all those works which have 

 come under my own and Prof. Andrews's notice, in which 

 abnormalities in annelids are recorded : — 



1. Andrews: " Proc. U.S. Nat. Mus.," vol. xiv., p. 283, 

 1891. 



2. Andrews : " Amer. Nat.," vol. xxvi., p. 725, 1892. 



3. Bell : "Ann. Mag. Nat. Hist.," vol. xvi., p. 475, 1885. 



4. Bell : " Proc. Zool. Soc , Lond.," 1887, p. 3. 



5. Bonnet: *' Qiuvres d'Hist. Nat. et de Phil.," vol. i., 

 p. 167 seq. 1779. 



6. Breese : West Kent Nat. Hist. Soc, 187 1. 



7. Broome: "Trans. Nat. Hist. Soc." Glasgow, 1888, 

 p. 203. 



8. Billow: "Archiv. f. Naturg," vol. xlix., 1883. 



9. Brunette: "Travaux de la Sta. Zool. de Cette," p. 8, 

 Nancy, 1888. 



10. Claparede : " Les Chaet. du Golfe de Naples," p. 436, 

 1868. 



11. Fitch: "Eighth Report on Insects of State of New 

 York," appendix, p. 204 seq. Albany, 1865. 



12. Foster: Hull Scientific Club, February, 1891. Reported 

 in weekly sup. Leeds Mercury. 



13. Friend: " Science Go sip," 1892, pp. 108, 161. 



14. Grube: "Archiv, f. Naturg.," vol. x., p. 200, 1844. 



15. Horst : " Tydsch. ned. Dierk. Veren," 2nd ser., D.I., 

 Af. i., p. xxxii, 1882. 



16. Laugerhaus : "Nov. Act., K.L.C.D. Acad.," vol. xiii,, 

 p. 102, 1879. 



17. Marsh: "Amer. Nat.," vol. xxiv., p. 373, 1890. 



18. Macintosh : " Challenger Reports," vol. xii., 1885. 



19. Robertson: "Quart. J. Mic. Soc," vol. xv., p. 157, 

 1867. 



20. Zeppelin: " Zeit. f. Wiss. Zool.," vol. xxxix., p. 615 

 seq. 1883. 



21. Catalogue Terat. Spec, in Mus. Roy. Coll. Surgeons, 

 London, 1872. Hilderic Friend. 



The Zero Point of Dr. Joule's Thermometer. 



In the course of a discussion on "Exact Thermometry" I 

 described (Nature, vol. xli. p. 488) the results obtained by 

 heating thermometers for a considerable time to 280° and 356° ; 

 and pointed out by means of a diagram that at 356°, after about 

 ten hours, the rise of the zero point became — at any rate approxi- 

 mately — a rectilinear function of the loijarithm of the time ; 

 though at 280", even after more than 300 hours' heating, the 

 \ ise appeared to be rather more rapid than would correspond to 

 ach a simple relation. 



Dr. Joule observed the rise of the zero point of a thermo- 

 meter at the ordinary temperature during a course of no less 

 than thirty-eight years (" Scientific Papers,' vol. i. p. 558), and it 

 occurred to me that it would be of interest to ascertain the rela- 

 tion to the logarithm of the time in this case also. 



The following table contains the dates of Dr. Joule's observa- 

 tions ; the total number of months from the date when the first 

 reading was taken ; the corresponding logarithms ; the total rise 

 of the zero point in scale divisions (13 divisions to i^ F.) ; the 

 total rise calculated from the formula R = 65 log. / - 4*12, 

 where t is the time in months ; and lastly the differences 

 between the observed and calculated zero points. 



The agreement between the observed and calculated values is 

 certainly remarkable, and the + and - differences are evenly 

 distributed. 



Ten years have now elapsed since the last reading was taken, 

 and if the thermometer is still in existence it would be of great 

 interest to know what further rise has taken place in its zero 

 point. According to- the equation the reading should now be 

 13 86. SvDNEY Young 



University College, Bristol, January 20. 



THE APPROACHING SOLAR ECLIPSE, 

 APRIL 15-16, 1893. 



'X*HE total solar eclipse of April 15-16, 1893, is not 



■■- only one of the longest of the century, but is the 

 last of the century from which we are likely to get any 

 addition to our knowledge of Solar Physics. The longest 

 duration of totality of this eclipse is 4 minutes 46 seconds, 

 and as the path of the moon's shadow lies to a great 

 extent on land, there is a considerable choice of possible 

 stations with long durations of totality. Commencing 

 in the Southern Pacific the line of totality passes in a 

 north-easterly direction and enters Chili at Charanah in 

 29° southern latitude, crosses the South American 

 continent, and issues at Para Cura, a village near Ceara, 

 at the north-east corner of Brazil, in latitude 3" 40' south. 

 It crosses the Atlantic at its narrowest part and enters 

 Africa at Point Palmerin, near Joal, almost midway 

 between Bathurst and Dakar, and in latitude 14' north ; 

 the shadow finally leaving the earth in the interior of 

 Northern Africa. The eclipse will be observed by several 

 parties of astronomers in Chili, Brazil, and Africa, there 

 being almost absolute certainty of fine weather in Chili 

 and Africa, and a reasonable probability in Brazil. 



The English arrangements to observe the eclipse have 

 been made by a joint committee of the Royal Society, 

 the Royal Astronomical Society, and the Solar Physics 

 Committee of the Science and Art Department^ South 

 Kensington ; Dr. A. A. Common, LL.D., F.R.S., under- 

 taking the duties of Secretary. Two expeditions will be 

 sent from England, one to Africa and the other to Brazil, 

 the expenses being defrayed by a grant of ^600 from the 

 Royal Society. 



The African expedition will be in charge of Prof. 

 T. E. Thorpe, and will consist of Prof. Thorpe, Mr. A. 

 Fowler, Mr. Gray, and Sergeant J. Kearney, R.E. The 

 Brazilian expedition will be in charge of Mr. A. Taylor,- 

 who will have with him Mr. W. Shackleton. 



Prof. Thorpe and his party will leave Liverpool by the 

 British and African mail steamer on March 1 8th, arriving 

 at Bathurst on April 2nd. They will be met at Bathurst 

 by a gunboat kindly placed at the disp>osal of the 

 expedition by the Admiralty, and will be conveyed at 

 once to Fundium, a station on the Salum River, about 

 sixty miles from Bathurst ; this being the station selected 

 by the Committee from the three which were offered by 

 the French Government. The gunboat will remain with 

 the expedition, and the officers and crew will assist in the 

 preparations for and in the actual observations of the 

 eclipse. After the eclipse the party will be taken to 

 Bathurst on the gunboat, and will return to England by a 

 British and African mail steamer, if one is available. 

 From the time-tables of the steamers now published it 

 appears, however, that there will not be any mail steamer 

 available until the end of April, and in this case a cruiser 

 will meet the party at Bathurst and bring them to the 

 Canary Islands or to Gibraltar, from either of which 

 places they will be able to return by mail steamer, 

 arriving in England early in May. 



The members of the expedition to Brazil will leave 

 Southampton by the Royal Mail steamer on February 

 23 for Pernambuco, arriving at the latter place on March 

 12. They will take passage by the local mail steamers 

 to Ceara, at which place they will arrive about March 20. 



