OcTOiitR S, igoS] 



NATURE 



579 



Sivclsberg process, pot roasting, briquetting fine sulphides, 

 tlip Dwight and Lloyd sintering process, flotation processes, 

 ind the Macquisten process. While these metallurgical 

 inventions deal with base metals, it must not be forgotten 

 that the ores treated almost always contain appreciable 

 quantities of gold and silver, which they will concentrate 

 and save. 



.\ NEAT method of showing the .hydrolysis of salts as 

 a chemical lecture e.xperiment is described by Mr. B. L. 

 \'anzetti in the Gaszetta (vol. .xxxviii., ii., p. 98). An 

 ordinary test-tube is three parts filled with a solution of 

 gelatin coloured with litmus or with phenolphthalein 

 rendered pink by a trace of alloli. A solution of an easily 

 hydrolysed salt, such as ferric chloride, is poured on to 

 I he surface of the gelatin after the latter has set. In 

 a short time two zones become visible in the gelatin, one 

 of which, the lower, travelling more quickly through the 

 gelatin, is due to acid, which renders the phenolphthalein 

 colourless ; the second zone, at the surface of the gelatin, 

 is coloure^ by the hydroxide of the base. In the case of 

 ferric chloride this zone is dark brown and opaque, owing 

 to ferric hydroxide being formed. Coloured salts, such as 

 copper sulphate on cobalt nitrate, can also be conveniently 

 used. 



From the Cambridge University Press Warehouse, 

 Fetter Lane, we have received copies of three forms 

 designed to facilitate the astronomical computations of 

 time, azimuth, and latitude. These forms have been 

 arranged by Messrs. A. R. Hinlcs and H. K. Shaw, of 

 Trinitv College, for use in the Cambridge Geography 

 .School, and are somewhat similar to, but more elaborate 

 than, those used for some years past by the students at 

 the Royal College of Science, South Kensington. The 

 first form is for computing time or azimuth from observa- 

 tions of the sun's altitude, and the second for the analogous 

 computation from the altitude of a star, whilst the third 

 is set out for the computation of latitude from circum- 

 meridian observations of sun or star. Such forms are in- 

 valuable, especially to those observers who, knowing the 

 general methods, are yet a little hazy as to the details of 

 the computations, for unless one is making and reducing 

 the observations regularly it often occurs that the simplest 

 method of computing is but imperfectly remembered : hence 

 follows loss of time and unnecessary increase of labour ; 

 but on these forms every correction, every step in the com- 

 putation is clearly set out, and it becomes impossible for 

 the observer to forget a correction or to apply a wrong 

 function. In addition to this, each form contains a few 

 useful hints and a diagram to be filled in showing exactly 

 the angles measured. Whilst the forms appear to be other- 

 wise complete, we think it would enhance their value 

 were the entire formula employed inserted, because this 

 would often give the occasional observer a valuable re- 

 minder as to the exact form of computation he was employ- 

 ing. The forms are sold in strong envelopes, and the price 

 of each envelope, containing twelve copies of one form, is 

 one shilling net. 



Mr. Tho.mas Thorp, of Guildford, has issued a cata- 

 logue of the books on botany and gardening, zoology, 

 geology, mathematics and physics, offered by him for sale. 



A SUBJECT list of works of reference, biography, biblio- 

 graphy, the auxiliary historical sciences, &c., in the library 

 of the Patent Office has just been published at the Patent 

 Office, 25 Southampton Buildings, W.C. 



The second part of the second French edition of Mr. 

 W. Rouse Ball's " Recreations mathematiques et 



NO. 2032, VOL. 78] 



Problemes des Temps anciens ct moderncs " has just been 

 published by M. A. Hermann, Paris. The translation 

 follows the fourth English edition, and Mr. J. Fitz- 

 Patrick has added to it some new subjects of interest, 

 among them being parquetry or tiling, the game of 

 dominoes, and constructions for the squaring of the circ'e- 



OUR ASTRONOMICAL COLUMN. 



Comet Morehouse, 1908c. — Several observations of 

 comet 1908c are recorded in Xo. 4274 of the Astronomische 

 Nachrichien (p. 29, September 23). M. Chofardet, observ- 

 ing at Besancon on September 5, describes it as having 

 a round, nebulous head, of ninth magnitude and 2'-5 

 diameter, without any definite nucleus. A short, indistinct 

 tail was seen projecting from the head in a N.W. direc- 

 tion. On September b, 7, and S, Prof. Abetti, at .\rcetri, 

 found the comet to have an oblong nebulous appearance 

 without nucleus, its diameter being 2' and its magni- 

 tude 9-0. 



Herr Ebell continues the ephemeris published by Prof. 

 Kobold in a previous number, and the following is an 

 abstract therefrom : — 



Oct. 8 



Ephemeris i2h. 



a (true) 6 (true) 



h. m. p 



19 57'9 ■■■ +61 21- 



19 459 ■•• +57 59' 



19 ?6-i ... -t-54 30- 



19 2S-I ... 4-50 55 



M. 



„ 10 

 ,, 12 



,, 14 ... 19 2S-I ... 4-50 55-3 

 „ 16 ... 19 21-4 ... +47 177 



„ 18 ... 19 15-9 ... 4-43 40-0 .. 



„ 20 ... 19 11-3 ... 4-40 4-2 .. 

 ,, 22 ... 19 7-5 . 4-36 32-6 .. 



,> 24 ... 19 4-3 ... 4-33 67 .. 



The apparent positions of the 

 according to the .ihove pphenipri^. 



T. Berlin. 



leg r 

 0'20I0 . 



0'I942 . 

 0-1872 . 

 o'i8oi . 

 0-1730 . 

 0-1657 . 

 0-1584 

 0-1510 

 0-1436 



log A 



, 0-0154 

 , o-oioo 



0-0062 

 , o'oo43 



0-0C41 

 , 00058 

 . 0-0090 



0-0139 

 . C-0201 



Bright- 

 ness 



..4-8 

 ■■ 5-0 

 • S'3 



... 5-5 



• 57 

 •■ 5-9 

 .. 6-0 

 ..6-1 

 .. 6-0 



comet among the stars, 

 nre shown approximately 





Chart showing apparent path of Morehouse's Comet, October 8-24. 



on the accompanying chart ; it will be noted that the 

 comet passes quite close to the fourth-magnitude star 

 I Cygni on October 14. According to an observation made 



