February 13, 1896] 



NATURE 



35 



report is illustrated by maps, photographs, and diagrams ; and 

 the statistical tables are admirably compiled. 



The January number of the American Geologist contains an 

 account of the late Prof. J. D. Dana, with a portrait and biblio- 

 graphy. Mr. Warren Upham discusses the flow of glacial ice, 

 with especial reference to the views of Messrs. Fletcher and 

 Deeley, mentioned in these columns about a year ago. A de- 

 scription of cases of the flotation of sand, by Mr. F. W. Simonds, 

 and an essay on the use of Paljeontology as " The Timepiece of 

 Geolc^y," by Prof. Claypole, are among the other contents. 



The Annuaire of the Municipal Observatory of Montsouris 

 for this year has just come to hand ; the observations — meteor- 

 ological, chemical, and bacteriological — tabulated and discussed 

 in it, refer to the year 1894. Another Annuaire which we have 

 received is that of the Belgium Academic des Sciences, des 

 Lettres, et des Beaux-Arts. A full notice of the life and 

 mathematical works of Eugene Charles Catalan, with a portrait, 

 appears in this annual of the Brussels Academy. 



With the motto Magnus magnes ipse est globus terrestris, the 

 new international quarterly journal, Terrestrial Afagnetism, the 

 forthcoming publication of which was announced in these 

 columns a few weeks ago, has made its appearance. The 

 articles in the journal are: "On electric currents induced by 

 rotating magnets, and their application to some phenomena of 

 terrestrial magnetism," by Prof. A. Schuster ; " Die vertheilung 

 •des Erdmagnetischen Potentials in Bezug auf Beliebige Durch- 

 messer der Erde," by Dr. A. Schmidt ; and " Halley's Earliest 

 Equal Variation Chart," by Dr. L, A. Bauer, the map being repro- 

 duced in facsimile. There are also letters, notes, and reviews 

 dealing with terrestrial magnetism and cognate subjects. The 

 journal is published under the auspices of the Ryerson Physical 

 Laboratory, University of Chicago. 



We have had upon our table for some time a copy of Napier's 

 celebrated and rare work on the construction of logarithms — 

 ■" Mirifica Logarithmorum Canonis Constructio" — reprinted in 

 facsimile by M. A. Hermann, 8 Rue de la Sorbonne, Paris. 

 Napier's discovery of logarithms was announced in his " Mirifici 

 Logarithmorum Canonis Descriptio," published in 1614 ; but 

 the explanation of the method by which the logarithms were 

 calculated appeared in the "Constructio," a posthumous work 

 not issued until 1620. To this work, which M. Hermann has 

 now reprinted, Henry Briggs, who was one of the first to 

 recognise the value of logarithms, appended some notes. The 

 reprint will be valued by all students of the history of 

 mathematics. 



The Geological Society of London has just published a list of 

 the geological literature added to its library during the year 

 1895. As compared with the only previous issue in this form, 

 we note that while the price remains unaltered, the volume has 

 swollen to nearly threefold — an increase only partly accounted 

 for by the fact that the present list represents a whole year's 

 additions as against a half-year's in the previous one. The 

 omission of maps from the list, to which we drew attention 

 when the previous list was published, has been repaired ; maps 

 are entered under the names of the authors responsible for them 

 in the general list, but there are cross-references under " Maps" 

 m the subject-index. The publication will be found a most 

 useful one by all geologists. 



Three papers were read at the recent meeting of the In- 

 stitution of Mechanical Engineers, viz. : " Telemeters and Range- 

 Finders for Naval and other Purposes," by Profs. Barr and 

 Stroud ; "Calculation of Horse-power for Marine Propulsion," 

 by Lieut. -Colonel Thomas English; "Notes on Steam Super- 

 NO. 1372, VOL. 53] 



heating," by Mr. William H. Patchell. The paper by Profs. 

 Barr and Stroud was confined to a description of two instruments, 

 viz. (i) the range-finder which is now in use in the navies of 

 this and many other countries ; and (2) a small hand instrument, 

 identical in principle with that for naval use, but much more 

 portable and much simpler in its details. Lieut. -Colonel 

 English's paper called attention to a method of calculating, from 

 the results of a single sea-trial of one ship, the horse-power 

 necessary to propel another ship, of the same type, at any re- 

 quired speed. By this method it becomes practicable, with the 

 ordinary appliances of a shipyard, to approximate closely to 

 results which could otherwise be obtained only by the use of the 

 refined apparatus of a model tank. Mr. Patchell described a 

 number of superheaters, and gave the results of tests with them. 



The additions to the Zoological Society's Gardens during the 

 past week include a Klippspringer ( Oreotragus saltatrix, <J ) 

 from Nubia, presented by Commander Alfred Paget, R.N. ; 

 an Indian Wolf (Canis pallipes,i) from India, presented 

 by Mr. Duncan Darroch ; a Barn Owl {.Strix Jlaminea)^ 

 British, presented by Mr. Bernard R. White ; a Gould's 

 Monitor ( Varanus gouldi) from Australia, presented by Mr. 

 Arthur R. H. W. Leach; a Sharp-nosed Crocodile {Crocodilus 

 acutus) from Jamaica, presented by Mr. Arthur P. Cohen ; 

 a West African Love Bird {Agapornis pullaria) from West 

 Africa, presented by Mrs. Roberts; an Alpine Marmot 

 {Arctomys\ marmotta), European, a Yellow-headed Conure 

 (Conurus jendaya)ixom. South-east Brazil, deposited ; a Crested 

 Grebe (Podiceps cristatus), a Curlew {Numenius arquata), 

 British, purchased; a '^la.\a.cc3.n'P2Lr'czkQQt{Palieornis longicauda) 

 from Malacca, received in exchange ; two Rufous Rat Kangaroos 

 {Hypsipryrnnus rufescens, 6 6), born in the Gardens. . 



OUR ASTRONOMICAL COLUMN. 



The Astrophotographic Catalogue. — At the last meet- 

 ing of the Royal Astronomical Society, the Astronomer Royal 

 gave some particulars relating to the progress at Greenwich of 

 the international photographic star catalogue. A special staff for 

 dealing with this worK has been organised under Mr. Hollis, 

 and already 130 of the plates taken for the catalogue have been 

 measured. It is estimated that about 180 plates can be measured, 

 and 160 of them reduced in the course of a year, so that at this 

 rate the section allotted to Greenwich, comprising about l50,ocx> 

 stars, will be completed in five or six years. Assuming that the 

 other sixteen co-operating observatories are proceeding equally 

 well, the world will soon be in possession of a colossal catalogue, 

 comprising between two and three million stars. 



Orbit OF a Centauri. — Dr. Doberck, of the Hong Kong 

 Observatory, has revised the elements of the orbit of a Centauri, 

 which he determined in 1877, with the following results {Ast. 

 Nach., No. 3330). 



T ... 1876-02 



e ... 0-51184 



P ... 79-123 years 



a ... i8"-450 



The sum of the masses, as determined from these elements, is 

 2-3780 times the mass of the sun. Taking the parallax as o"75 

 the major semi-axis is 24-60 times the earth's distance from the 

 sun, so that the distances between the components are about the 

 same as those of the outer planets from the sun in our own 

 system. If the diameters of the stars are not very different from 

 that of our sun, each would appear from the other as a mere 

 star to unaided vision, the distance being too great to show a 

 disc. An ephemeris up to 1920 is given in the paper, as well as 

 a comparison of observations with the places calculated from the 

 adopted orbit. 



Comets of Short Period.— From an interesting article 

 on comets of short period, by Mr. W. E. Plummer {Knowledge, 

 February), we extract the following table, indicating the comets 

 which may with reasonable certainty be expected to reappear. 



