532 



NATURE 



[October i, 1903 



Report of the Paris Observatory for 1902. — In his 

 report of the Paris Observatory for 1902, M. M. Loevvy, the 

 director, describes in detail the various important series of 

 observations made at that observatory. 



In announcing that the last two volumes of the "Cata- 

 logue de rObservatoire de Paris " are ready for publica- 

 tion, M. Loewy gives a detailed account of the ci^-cum stances 

 which led to the inception and prosecution of the work 

 necessary for the publication of such a complete stellar 

 catalogue. 



For the determination of the latitude of the Paris Observ- 

 atory, 6530 measures of the absolute polar distances of 

 fundamental stars were made with the large meridian circle 

 during the year, and, in accordance with Sir David Gill's 

 proposals, 5063 observations of reference stars for the 

 astrographic chart were made. 



The observations for the redetermination of the difference 

 of longitude between Paris and Greenwich were completed, 

 and the concordance between the observations of the Paris 

 and Greenwich observers in the first series, which has been 

 completely reduced, is very striking. 



504 photographs of the moon for the " Atlas Photo- 

 graphique de la Lune," of which the sixth section has been 

 published, were taken with the large equatorial coud6. A 

 6-inch grating, for use with the smaller equatorial coud^, 

 has been ordered from America, and when this is received 

 it is proposed to carry out, systematically, similar researches 



ports for meridian circles. It will perhaps be remembered 

 that in the last report of the superintendent of the United 

 States Naval Observatory it was stated that since the 

 substitution of a brick pier for the marble pier that was 

 formerly used, the previously reported changes in azimuth 

 of the 6-inch Repsold meridian circle had entirely dis- 

 appeared. The experience of Prof. Hough is opposed to the 

 principle contained in that statement, viz. that brick piers 

 are superior to stone for this purpose. 



By a table of comparative expansions he shows that those 

 of granite, sandstone, &c., approximate more nearly than 

 that of brick to the expansion of iron, and therefore, with 

 iron fastenings, a stone pier will ensure a greater rigidity 

 of the instrument in regard to the pier ; from the same 

 table it is seen that brass fastenings are far more likely 

 t'j produce lack of rigidity than those made of iron. 



RECENT PAPERS ON METEORITES. 

 T'HROUGH the courtesy of Prof. Henry A. Ward, of 



Rochester, New York, we are able to reproduce for our 

 readers a photograph which gives a good idea of the form 

 and dimensions of the large mass of meteoric iron lying at 

 a place called Ranchito, near Bacubirito, in the province of 

 Sinaloa, Mexico. The existence of the mass was made 

 known to the scientific world by Prof. Barcena more than a 



Fig. I. — The Meteoric Iron of Bacubirito, Sinaloa, Mexico. 



in solar physics to those which are already prosecuted in 

 England and America. 



In connection with the " International Astrographic 

 Chart and Catalogue " fifty-six plates for the chart and 

 twelve for the catalogue were secured ; the printing of the 

 catalogue_ for zone +24° was completed, and it contains 

 the positions of 64,264 stars, whilst the publication of 

 zone +23° was commenced and the section oh. 4m. to 

 6h. 2om. completed. Altogether the positions of 21,855 stars 

 were completely measured for the catalogue, and the magni- 

 tudes of 35,630 stars belonging to zone -1-23° were deter- 

 mined during 1902. 



The Rigidity of Piers for Meridian Circles. — In 

 No. 3902 of the Astronomische Nachrichten, Prof. G. W. 

 Hough, of the Dearborn Observatory (U.S.A.), discusses in 

 detail the relative merits of brick and stone piers as sup- 



NO. 1770, VOL. 68] 



quarter of a century ago, and, later, its dimensions were 

 recorded by Prof. Castillo ; but until after the visit of Prof. 

 Ward there had been no published information as to the par- 

 ticulars of the occurrence. Prof. Ward, who is greatly in- 

 terested in meteorites, travelled from the city of Mexico to 

 Bacubirito, an extremely long, arduous, and expensive 

 journey, for the special purpose of examining the meteorite 

 in situ. It was found by him to be lying at the place speci- 

 fied, but to have only one end projecting from the ground. 

 Twenty-eight labourers were employed by him to excavate 

 round the mass and make it possible to determine the com- 

 plete form. After two days' work not only had this been 

 done but, through removal of the support from one side, the 

 large mass had been made to turn itself over. It is 13 feet 

 I inch long, 6 feet 2 inches wide, and 5 feet 4 inches thick. 

 Its irregularity of form and the character of the surface are 

 manifest from Fig. i. The mass is estimated to weigh 



