lOO 



NATURE 



[October 2, 1919 



arrived at are as follows : — (i) The cooling of bread 

 takes place in three stages : a steam period, a con- 

 densation period, and a drying period, the rate of 

 loss of moisture of the first being four times as great 

 as that of the drying period and five times that of 

 the condensation period. (2) No marked loss of mois- 

 ture from the centre of the loaf occurs until after 

 100 hours, and within the latter period the zone of 

 drying is a layer only i in. thick adjacent to the outer 

 crust. (3) The loss of water from a loaf on keeping 

 is not responsible for stateness. (4) As the loaf 

 becomes stale there is a fall in the amount of soluble 

 extract of the bread-crumb, followed bv a rise, the 

 soluble starch falling rapidly between six and twentv- 

 four hours' cooling. This supports Lindet's view that 

 stateness is due to the retrogression of soluble starch. 

 A similar fall and rise of soluble extract has been 

 observed with starch pastes. Capt. VVhymper con- 

 siders that stateness may be attributed to (i) deposi- 

 tion of solid starch in the bread-crumb by change of 

 temperature and accelerated by the pre-existence of 

 solid starch particles ; and (ii) partial polymerisation 

 of starch independent of the deposition mentioned, 

 which tends to crumble the gelatinous nature of ihe 

 bread-crumb. Changes occurring in the proteins of 

 the bread mav also be a cause of stateness 



yiessrs. Bailliere, TindaJl, and Cox have in the 

 press for appearance in their Industrial Chemistry 

 Series: — "Explosives," E. de Barry Barnett; "The 

 Industrial Gases," Dr. H. C. Greenwood; "Animal 

 Proteids," H. G. Bennett; and "The Carbohydrates," 

 Dr. S. Rideal. The following volumes are in pre- 

 paration for the same series : — " Fats, Waxes, and 

 Essential Oils," W. H. Simmons; "Silica and the 

 Silicates," J. A. Audlev; "The Rare Earths and 

 Metals," Dr. E. K. Rideal; "The Iron Industry," 

 A. E. Pratt; "The Steel Industry," A. E. Pratt; 

 "Gas-works Products," H. H. Gray; "Organic 

 Medicinal Chemicals," M. Barrowcliff and F. H. 

 Carr; "The Petroleum Industrv," D. A. Sutherland; 

 "Wood and Cellulose," R. W. Sindall and W. 

 Bacon; "Rubber, Resins, Paints, and Varnishes," 

 Dr. S. Rideal ; and " Economic Fuel Production in 

 Chemical Industry," Dr. H. S. Taylor. 



Erratum. — On p. 84 of N.-vture of September 25, 

 in the Table in column two, 954 appeared under 

 S(aturn) in some copies as 54, the 9 having been 

 broken off during printing. 



OUR ASTRONOMICAL COLUMN. 



The Tvi^ENTY-FOUR-HOUR Day. — ^The spirit of 

 standardisation and unification is abroad, and one of 

 its latest manifestations is the attempt to reduce the 

 various methods of time-reckoning to a single system. 

 Astronomers have made an important contribution to 

 this end in deciding to commence the astronomical 

 dav at midnight instead of noon. This reform will 

 commence in the year 1925, an earlier date being in- 

 convenient for the various nautical almanacs. While 

 astronomers will gain, on the whole, by the change, 

 yet in some respects, notably in the case of sets of 

 observations extending on both sides of midnight, it 

 will cause inconvenience ; this gives them a certain 

 claim to ask for some sacrifice on the part of the 

 general public in order to achieve the further unifica- 

 tion which is now desired ; this is the substitution 

 of 24-hour reckoning for the present system of a.m. 

 and p.m. 



Twenty-four-hour time has long been used in Italy ; 

 it was introduced into the British Army last year, 

 and a few railway companies already use it in their 

 time-tables, where its convenience is so manifest that 

 it is surprising that its introduction has been so tardy. 



NO. 2605, VOL. 104] 



The majority of social functions take place in the 

 afternoon or evening, and it undoubtedly is somewhat 

 more troublesome to say seventeen than five, or 

 twenty-one than nine. Punch made some amusing 

 play on this subject when the reform was suggested 

 in 1885 ; possibly this had something to do with the 

 failure to carry it at that date. However, the fact 

 that astronomers could not then agree to alter the 

 astronomical day deprived the scheme of its driving- 

 power. The auspices are now more favourable, and 

 the report of the Committee, consisting of seven 

 members, just appointed by the Home Secretarv Mil 

 be awaited with interest. 



Comets. — Using observations made on August 21, 

 29, and September 7, Messrs. Braae and Fischer- 

 Petersen have deduced the following elliptical orbit 

 of the comet 1919b : — 



T = 1919 Oct. i6-86i G.M.T. 



(0 =129° 321 l'"j 



^1 = 310° 43 4i'li9i9o 



z = 19° ir45J 

 The elements are extremely close (within about 5' in 

 each case) to Gould's elements for 1847 when "cor- 

 rected for precession. The error of the middle place 

 in longitude (great circle) is -0-50', in latitude -t-o-5i'. 

 The period adopted is simply 'the observed interval 

 between the two perihelia, uncorrected for perturba- 

 tions. 



Grerimnch Midnight. 



log rt= 1-23860 

 log £■ =9-98767 

 log ^ = 968544 

 Period 72-095 years 



Oct. 



N. Dei 



25 14 

 20 52 



16 46 



12 49 



8 ^^ 



The comet will be observable as a morning object in 

 Europe until early in December; after that it will 

 pass to the south of the sun, and will be better placed 

 U)r southern observers. It is very desirable to observe 

 it as long as possible, in order to place the elliptical 

 character of its orbit beyond a doubt. 



The physical appearances of the three visible comets 

 are discussed in L'Astronomie for September. 1919a 

 (Kopff) appeared as a circular nebulosity some 3' in 

 diameter, gradually increasing in brightness towards 

 the centre, where there was a nucleus of the 12th 

 mag.; no trace of a tail. 1919b (Metcalf-Brorsen) 

 was visible to the naked eye on September 5, in 

 spite of strong moonlight. In the telescope it ap- 

 peared as a large nebulosity, with eccentric con- 

 densation, and a short but broad tail pointing S.W. 

 1919c (Metcalf-Borrelly) appeared earlv in September 

 as a pale nebulosity, 2' in diameter, with slight cen- 

 tral condensation; observation difficult owing to 

 moonlight. 



Minor Planets. — A sixth member of the interest- 

 ing Trojan group of planets (the mean motion of 

 which is the same as that of Jupiter) was found in 

 March last, and provisionally designated 1919 FD. 

 Its mean longitude is 60° greater than that of Jupiter. 

 Prof. Cohn gives the following elements :— 



Epoch 1919 March 19-5 G.M.T. 

 M„= 88° 48' 18-9" 



a = 78° 46' 7-8"1 



S=336' 55' lo-q"- 1919-0 



i = 21° 56' 49'8"j 



*= 4° 55' 43"4" 

 ,j =303-190" 

 log « = o-7i2i94 , 



Four of the Trojans have longitude 60° greater than 

 Jupiter, and two 60° less. 



