154 



NATURE 



[October 25, 1917 



of cement kilns are mentioned. As regards the pro- 

 vision of shelter, Prof. Morgan points out that in the 

 production of Portland cement the chemist is supreme, 

 and very few stable structures are built nowadays m 

 which it is not employed. Glass is another important 

 material in building construction of which the manu- 

 facturer requires the continual intervention of the 

 chemist. Chemistr}' is no less important in industries 

 providing the munitions of war. As the raw materials 

 for the latter are obtained from coal-tar, which also 

 supplies the organic compounds necessary for the pro- 

 duction of dyes and drugs, the latter industries become 

 interdependent with that of munition-making. The 

 synthesis of one dye or drug is not only important 

 per se, but also frequently the incentive in the syn- 

 thesis of others. Thus, since the synthetic production 

 of indigo many other vat dyes not found naturally have 

 been produced. 



With reference to our note on ferro-concrete ships 

 (Nature, October ii, p. 114), Engineering for October 

 19 contains an interesting account of the launch of the 

 ferro-concrete ship Beton I., with illustrations from 

 photographs. As indicated in our former note, the 

 ship was built bottom upwards and launched in this 

 position. On taking the water, the air contained in 

 the structure caused the draught to be comparatively 

 small, the water plane was therefore large, and the 

 vessel was in stable equilibrium. On permitting some 

 of the air to escape, the vessel sank in the water; 

 owing to the shape of the bottom, the area of the 

 water plane was thus reduced considerably. Ulti- 

 mately a draught was reached in which the centre of 

 gravity was above the centre of buoyancy, and an 

 upsetting couple was established which caused the 

 ship to turn right side upwards, in which position 

 stable equilibrium was again attained. The upright- 

 ing, to begin with, proceeded slowly, and accelerated 

 in the intermediate stages in which the couple was 

 greatest, and then again more slowly. The turning 

 took place very neatly, without any shock, and 

 the vessel had then, of course, to be emptied of 

 water. 



Among the forthcoming books of Mf. Humphrey 

 Milford, of the Oxford University Press, are the follow- 

 ing : — "Agriculture in Berkshire," J. Orr (a survey 

 made on behalf of the Institute in Agricultural Econo- 

 mic, University of Oxford), illustrated; "A Weather 

 Calendar," Mrs. H. Head, with a bibliography; "Dr. 

 John Radcliffe, his Fellows and Foundations," J. B. 

 Nias; "Dynamic Psychology," R. S. Woodworth (The 

 Jesup Lectures) ; " Aristotle : Meteorology," edited by 

 F. H. Fobes; "The Princijiles of Acidosis and Clinical 

 Method for its Study," A. W. Sellards ; "The Self and 

 Nature," De Witt H. Parker; "The Problem of Space 

 in Jewish Mediaeval Philosophy," 1. Efros. 



The new announcements of Messrs. Longmans and 

 Co. include : — " Rhododendrons and their Hybrids," by 

 J. G. Millais, with coloured plates by A. Thorburn, 

 B. Parsons, E. F. Brennand, and W. Walker; " Mystic- 

 ism and Logic and other Essays," by the Hon. B. 

 Russell; "Reality and Truth: a Critical and Con- 

 structive Essay concerning Knowledge, Certainty, and 

 Truth," by the Rev. Prof. J. G. Vance; and "The 

 Works Manager To-day," by S. Webb. 



Messrs. J. M. Dent and Sons, Ltd., will shortly 

 publish in "Everyman's Library" an anthology from 

 the works of the late Prof. William James, which 

 will form an introduction to the writings of the 

 philosopher. The book is edited by Prof. C. Bakewell, 

 of Harvard University. 



NO. 2504, VOL. 100] 



OUR ASTRONOMICAL COLUMN. 

 The Hunter's Moon. — The following particulars as 

 to the visibility of the moon during the next fourteen 

 days may be of interest : — 



Altitude 

 Rises Souths Sets on meridian 



P.M. I'.M. A.M. 



Oct. 25, 2.26 Oct. 25, 7.52 Oct. 26, 1.32 31 



26, 2.45 20, 8.43 27, 2.57 37 



27, 3- 5 27, 9-35 28, ^.22 44 



28, 3.26 28, JO. 28 29, 5.47 50 



29, 3-49 29, 11.22 30. 7.13 55 



A.M. 



30, 4.19 31, O.I9 31, 8.34 59 



31, 4.56 Nov. I, 1. 17 Nov. J, 9.49 62 

 Nov. I, 5.41 2, 2.15 2, 10.50 63 



2, 6.38 3, 3. 1 1 3, 11.39 62 



8, 0.15 



7- 4 



'•39 45 



The times along the same horizontal line refer to the 

 same appearance of the moon above the horizon. 



Full moon occurs at 6.19 a.m. on October 30, and 

 last quarter on Nov. 6 at 5.4 p.m. It may be noted 

 that the half-moon gives only about one-tenth of the 

 amount of light given by the full moon at the same 

 altitude. 



The Orbit of Comet 1914c. — A definitive investiga- 

 tion of the orbit of comet 1914c (Neujmin) has been 

 made by J. Sviirdson {Ast. laktt. Stockholms Obs., 

 Band 10, No. 6). The comet was never very bright, 

 but was observed during a period of 182 days, from 

 June 27 to December 22. Corrections have been ap- 

 plied for the perturbations due to Jupiter, and it is 

 concluded that the observations are best satisfied by 

 the following hyperbolic elements : — 



T=I9I4, July 30- 1 5783 ±0-13374 Berlin M.T. 



«,= i4° 2 i2-5'±92-4 ] 



^ = 270° 18' 267"± 3-3" [1914-0 



/ =» 71° 2' i8-4"± ioi"j 



log ^ =3747131 ±0000243 

 e = I -003672 ±0-000296 



The orbit is remarkable for the exceptional value of 

 the peVihelion distance ; in this and other respects it 

 shows considerable resemblance to the orbit of the 

 comet of 1729. 



Maximum of Mira Ceti. — This well-known variable 

 star may be expected to reach a maximum about the 

 end of the current month. The magnitude ranges 

 from 20 to 96 in a period of about 331 days, but the 

 period and magnitude at maximum are subject to 

 variation. The star is now well placed for observation, 

 crossing the meridian near midnight, and thus being 

 above the horizon for practically the whole night. On 

 October 20 the star was of about 4th magnitude. 



Brester's Theory of the Sun. — In anticipation of a 

 further volume on the constitution of the sun, Dr. A. 

 Brester has issued the introduction and general con- 

 clusions in pamphlet form (La Have : P. van Stockum 

 et Fils, 1917). As is well known, Dr. Brester does not 

 accept the general view that the surface of the sun is 

 subject to violent disturbances, and seeks to explain 

 solar phenomena on the basis of a relatively tranquil 

 gaseous globe which is practically undisturbed by con- 

 vection currents. The solar gases decrease in density 

 and luminosity from the centre outwards, but on 

 account of their opacity their light never reaches us. 

 The photosphere is a condensation stratum which is 

 rendered luminous in the same way as a mantle in an 

 ordinary gas flame, while a sun-spot is a perforation 



