March 



1 910] 



NA TURE 



19 



benzene at temperatures ranging from —78° C. to 25-8° C. 

 At the lower temperatures the statical method is not 

 sufficiently exact, and hence the vapour pressures were 

 measured by saturating pure oxygen, prepared electrolytic- 

 ally, with the vapour of the substance, the latter being 

 maintained at a constant temperature. The amount of 

 vapour carried away by the oxygen was determined by 

 combustion, full details being given of the precautions 

 necessary for exact working. The method was shown to 

 be capable of measuring vapour pressures down to 

 0-005 mm. of mercury. The experimental results were 

 compared with Nernst's formula for the calculation of 

 vapour-pressure curves, and for toluene, naphthalene, and 

 benzene ; the agreement was found to be satisfactory. 



An interesting article appears, in Engineering for 

 February 25 giving particulars of a new shrinking and 

 tempering shop for guns at Woolwich Arsenal. Modern 

 built-up guns have steel tubes and liners which require 

 oil-hardening, and as these guns are sometimes of great 

 length, it will be understood that adequate means must 

 be provided for lifting the guns to considerable heights. 

 It was decided that the new building should be 300 feet 

 long in the clear (the first part to be constructed being 

 150 feet), 60 feet wide, and 90 feet high from the floor- 

 level to the gantry rail. It was also stipulated that an 

 electro-hydraulic travelling crane should be installed cap- 

 able of lifting 120 tons, and of travelling with its load at 

 a speed of 75 feet per minute, the speed of the cross 

 traverse under similar conditions being 35 feet per minute. 

 Another requirement of this crane is ability to lower a 

 weight of 60 tons at a speed of 500 feet per minute, this 

 being of great importance on account of the necessity of 

 dipping the guns rapidly into the oil in the process of 

 hardening. Two deep pits, each 1 1 feet in diameter, are 

 provided for oil-hardening tanks ; also one shallower over- 

 fjow pit, a driving pit 18 feet in diameter with an anvil 

 bottom, and a shrinking pit. 



: Messrs. C.-issell asd Comp.any, Ltd., have commenced 

 Ihe publication, in fortnightly parts, sold at one shilling 

 tiet each, of Mr. Richard Kearton's " Nature Pictures." 

 rhe illustrations are beautifully reproduced, and are 

 accompanied by descriptive text. The work will .be com- 

 pleted in twenty-four parts, and we propose to review it 

 when the serial publication is complete. 



A SECOND edition of an essay entitled " The Finest Walk 

 in the World," by Miss B. E. Baughan, which originally 

 appeared in the Spectator, and was published recently in 

 aamphlet form with numerous illustrations, has been issued 

 by Messrs. Whitcombe and Tombs, Ltd., of Addle Hill 

 ["arter Lane, London. The walk, some thirty-three mil 

 n length, is in the neighbourhood of the celebrated Milfoi J 

 Sound, in the south-west corner of New Zealand. Judg- 

 ng from the beautifully reproduced photographs and the 

 ?nthusiastic descriptive text which accompanies them, the 

 R'alk must reveal a succession of panoramic views of 

 Sature at her loveliest. 



The annual report of the board of regents of the Smith- 

 sonian Institution, showing the operations, expenditures, 

 jnd condition of the institution for the year ending June 

 JO, 190S, has been received. As usual, the general 

 ippendix of the volume, running to some 684 pages, will 

 Tiake the widest appeal to readers. It contains a repre- 

 sentative selection of papers and addresses by distinguished 

 nen of science dealing with notable current scientific re- 

 searches. Some of these are translations into English from 

 jerman, French, and Swedish publications, others have 

 appeared in Nature fro.-n time to time, and the remainder 

 NO. 2105, VOL. 83] 



are from American and British authors, some being 

 original, while others are reprints. The following con- 

 tributions may be mentioned : — Sir Joseph Thomson's 

 Adamson lecture to the University of Manchester, on the 

 light thrown by recent investigations in electricity on the 

 relation between matter and ether; Prof. J. W. Gregory's 

 contribution to the Congr^s g^ologique international, 

 Mexico, 1906, on climatic variations: their extent and 

 causes ; Prof. J. Joly's address to the geological section 

 of the British Association at Dublin in 1908, on uranium 

 and geology; Captain H. G. Lyons's lecture to the Royal 

 Geographical Society, on some geographical aspects of the 

 Nile; Prof. Ronald Ross's address to the Oxford Medical 

 Society in 1906, on malaria in Greece ; and Prof. Silvanus 

 P. Thompson's Kelvin lecture of 1908 (abridged and revised 

 by the author), on the life and work of Lord Kelvin. 



OUR ASTRONOMICAL COLUMN. 



Astronomical Occurrences in March: — 

 March 3. 12b. cm. Venus stationarv. 



7. oh. 39ni. Uranus in corjunction with the Moon 



(Uranus 3" 34' N.). 



8. gh. 17m. Venus in conjunction with the Moon 



(Venus n" 52' N.). 

 10. 6h. om. Vesia in conjunction wiih the Moon (Vesti 



1° 9' N.). 

 13. 2h. 45m. Saturn in conjunction with the Moon 



(Satuin o" 58' N.). 

 15. iQh. 17m. Mars )n conjunction with the Moon 



(.Mars i' i6'N.\ 

 18. I7h. om. Venus at greatest brilliancy. 

 25. i8h. 2im. Jupiter in conjunctitn with the Mood 



(Jupiter 2' 31' S.). 

 30. i8h. om. Jupiter at opposition to the Sun. 



• Comet igioa. — In these columns last week reference was 

 made to two drawings, of comet 1910a, which are now- 

 reproduced from the Comptes rendus (No. 7, p. 370, 

 February 14). They were made by M. Esclangon, and 

 illustrate the remarkable change which took place in the 

 appearance of the comet's head between January 22 

 and 30. 



January 22. 



January 30. 



M. Esclangon points out that such apparent changes 

 mav be produced in two ways: — (i) by actual changes in 

 the comet itself ; (2) or by the different angles at which 

 it is presented to the observer. While great real changes 

 undoubtedly took place in comet 1910a, a certain propor- 

 tion of the apparent change can be explained by the 

 aifTerent aspect, for on January 22 the angle made by the 

 tail with the line-of-sight (comet-earth) w^as 96°, whilst 

 on January 30 it was 133°; but, apart from this, there 

 was a real change in brightness and in the condensatior^ 

 of the nucleus consequent upon the comet's recession from 

 the sun; on the former date its distance was about 0-25, 

 on the latter about 0-55, astronomical unit. 

 - M. J. Comas Sola also made a special study of the 

 figure of the comet, and gives his results in the same 



