496 



NA TURE 



\_March 24, 1887 



A Health Exhibition will be opened in Warsaw on May 

 15 next. 



An International Agricultural Exhibition of Tools and Imple- 

 ments will be held at Parma in September next. 



The Royal Bavarian Academy of Sciences is coUecti ng the 

 numerous tre atises of Joseph Fraunhofer, hitherto dispersed in 

 numberless serials, and is about to publish them in one volume. 



Prof. Verneuil and L. H. Petit have i-sued the first num- 

 ber of a periodical publication called " Etudes experimentales 

 et eliniques sur la Tuberculose." It is published by means of 

 a fund especially raised for the promotion of the study of 

 tuberculosis. 



M. H. Gadeau de Kerville has just published a work on 

 evolution. It is entitled " Causeries sur le Transformisme," and 

 contains an exposition of the facts and theories upon which the 

 doctrine of evolution is based. 



A BOOK on therapeutics, by M. G. Hayem, Profes sor in the 

 Paris Medical School, has just been published. 



The February number of the Italian Geographical Bulletin 

 contains a detailed account, by Dr. G. A. Colini, of the rich 

 ethnological collection recently presented to the Prehistoric and 

 Ethnographic Museum of Rome by General Gene, Commander 

 of the Italian possessions on the East Coast of Africa. The 

 collection includes a great variety of objects, such as arms, cos- 

 tumes, implements, ornaments, utensils from Abyssinia, Somali 

 Land, and the Afar (Danakil) country. Amongst them are 

 baking-ovens, braziers, incense-burners, cooking-utensils, pestles 

 for grinding coffee, pepper, durrha, &c. ; baskets, matting, 

 veils, robes, loin-cloths, wooden sandals, lamps, swords, match- 

 lock guns, knives, hairpins, &c., illustrating the arts and indus- 

 tries of the East African peoples. 



We have receivei the four latest Bulletins of the U.S. 

 Geological Survey (Nos. 30-33). No. 30 contains Mr. C. D. 

 Walcott's second contribution to " Studies on the Cambrian 

 Faunas of North America." A systematic review of our present 

 knowledge of fossil insects, including myriapods and arachnids, 

 by Mr. S. H. Scudder, is presented in No. 31 ; and an elaborate 

 account of mineral springs of the United States, by Dr. A. C. 

 Peale, in No. 32. No. 33 is made up of notes, by Mr. J. S. 

 Diller, on the geology of Northern California. 



Mr. Edward Cookworthy Robins, whose collected papers 

 on technical education and applied science, buildings and fittings, 

 &c., were reviewed in Nature some time ago, is now engaged 

 on a general work of reference on the same subject. It will 

 appear shortly under the title of "Technical School and College 

 Buildings," in a quarto volume of about 250 pages, with upwards 

 of 100 full-page illustrations, plates, and maps. 



In the Proceedings of the American Antiquarian Society 

 (vol. iv. p. 62) Mr. Frederick W. Putnam gives an account of 

 twelve jade objects found in Nicaragua and Costa Rica, ten of 

 which were ornaments made by cutting celts into halves, quarters, 

 or thirds, a portion of the cutting edge of the celt remaining on 

 each piece. Mr. O. W. Huntington, who was asked to report 

 upon the nature and source of the material of these ornaments, 

 is of opinion that the specimens ''are unquestionably Chinese 

 jade." They have, he says, "all the characters of that mineral, 

 .although the largest specimen from Costa Rica is rather unusual 

 in its colour, and would not be taken for jadeite at sight." The 

 Amaican Naturalist, which calls attention to these facts, thinks 

 "it will now be in order to collate during the next ten years the 

 evidence for and against contact between the Orient and the 

 western shores of America." 



Some interesting notes from Venezuela have lately been 

 contributed by Dr. Ernst, of Caracas, to the Proceedings of 

 the Berlin Anthropological Society. The writer brings together 

 much valuable information as to the manners and customs of 

 the aboriginal population, and about their food, ornaments, 

 implements, weapons, and canoes. 



The additions to the Zoological Society's Gardens during 

 the past week include a Mauge's Dasyure {Dasyurus maugai 9 ) 

 from Australia, presented by Mr. W. Miller ; two White- 

 crowned Pigeons [Columba leucocephala) from the West Indies, 

 presented by Lieut. -Colonel Dawkins ; two Long-tailed Grass 

 Ymz\ie%{Pocphila aciiticauda) from Australia, presented by Mr. 

 Walter Burton ; an Algerian Tortoise {Testudo ?naurilanica) 

 from North Africa, presented by Mr. J. M. Green; a European 

 Pond Tortoise {Emys europica). South European, presented by 

 Mr. Henry Garle ; five European Tree Frogs (Hyla arborica), 

 European, presented by Mr. F. W. Green ; an Axis Deer 

 {Cervus axis 9 ), a Collared Fruit Bat (Cynonyctcris collaris), 

 sixteen Puff Adders (Vipera arietans), born in the Gardens. 



OUR ASTRONOMICAL COLUMN 



Researches on the Diameter of the Sun. — Herr 

 Auwers has published in the Sitzungsberichte der Koniglicli 

 Prcussischen Akademic der Wissiuschaften %u Berlin, 1886, 

 No. 1., the first part of an elaborate investigation of the value 

 of the sun's diameter as found from meridian observations, and 

 of the apparent variations thereof The discussion now pub- 

 lished refers to variations in the mean annual values only of 

 the diameter. The series of observations discussed are the 

 meridian observations of the sun made at Greenwich, 1851-83 ; 

 at Washington, 1866-S2 ; at Oxford (Radcliffe Observatory), 

 1862-83 ; and at Ntuchatel (transit observations only), 1862-83. 

 The "personal equations" of the various observers are first 

 determined on the supposition that there may be periodic annual 

 variations, both in the horizontal and vertical diameters of the 

 sun, such for instance as have been supposed by Secchi and 

 others to e.xist, with a period corresponding to the sunspot cycle. 

 The first determination of "personal equation" is therefore 

 made by comparing observations taken in each year with others 

 taken in the same year only. The resulting diameters are, how- 

 ever, such as to convince Herr Auwers that, although inequali- 

 ties exist in each of the series of observations discussed, their 

 comparison with each other and with the sunspot curve is 

 sufficient to show that they have no connexion either with the 

 latter or with a progressive change, but are most probably due 

 to uncorrected "personal equations." A second determination 

 of these on the assumption that, for some observers at least, 

 they are liable to change, but that the sun's diameter is not 

 subject to annual variation, leads to much more satisfactory 

 results, and is regarded by Herr Auwers as the correct solution 

 of the problem. The effect of personality on the deduced solar 

 diameter, which on the average, for an individual observer, 

 amounts to about l" (sometimes 3", 4", and even 10"), m.ay be 

 inferred from the fact that the values of the horizontal and vertical 

 diameters of the sun, deduced from thirty-three years' observa- 

 tion with the Greenwich transit-circle, and referred to the mean 

 of Dunkin, Ellis, Criswick, and J. Carpenter, as standard, are 

 respectively 32' 2"'48 and 32' 2"'oo ; whilst, referred to the 

 mean of fifty-four observers, the same observations give, for the 

 horizontal and vertical diameters respectively, the values 32' 

 I "-99 and 32' 2" 73. 



Comet 1887 b (Brooks, January 22). — The following 

 ephemeris for Berlin midnight, is by Dr. R. Spitaler {Astr. 

 Nach. No. 2776). 



1807 R.A. Decl. Brightness 



The brightness on January 24 is taken as unity. 



