March ii, 1909] 



NATURE 



51 



caused by the existence in the sun of irregular density- 

 gradients, comparable in magnitude with the vertical 

 gradient in the earth's atmosphere, will explain them 

 efficiently. 



The Consutl'tios of tme Sun. — In No. i, vol. xxix., 

 of the Astropliysical Journal, Hcrr J. F. Hermann Schulz 

 again brings forward the theory that the nucleus of the 

 sun is in a liquid state. This theory, in its earlier forms, 

 was propounded by Kirchhoff, modified by ZoUner, and, 

 about twenty years ago, advocated by Herr Schulz, but the 

 prevailing ideas concerning the sun's temperature then 

 rendered it improbable. 



However, in the light of the recent researches of Moissan 

 and others, from which it may be deduced that the mean 

 temperature of the sun is about 5400° C, Herr Schulz 

 believes that a liquid nucleus best explains the observed 

 phenomena, and on these lines he revives his theory. He 

 further argues that various stellar phenomena may be 

 explained on the assumption that many stars, too, are 

 not entirely gaseous. The paper in which the discussion 

 was included was read before the last meeting of the 

 .Astronomische Gesellschaft in Vienna, September, 1908, 

 and also appears as an abstract from the Viertcljahrs- 

 schrift der Astronomischcn Gesellschaft, part iv., 1908. 



Still another solar theory is expounded in No. 4305 of 

 the Astronomische Nachrichtcn. In this paper M. .'\. 

 Amaftounsky, of Kichineff, explains the phenomena of sun- 

 spots, metallic and gaseous prominences, sun-spot zones, 

 &c., on the assumption that spots are caused by the out- 

 rush of heated vapour from the sun's lower atmosphere, 

 and the tilling in of the funnels thus formed by the photo- 

 spheric clouds. The agreement of observed phenomena 

 with the phenomena which would follow were the theory 

 correct is discussed in detail. 



Radial Velocity of a Persei. — From thirty-seven 

 spectrograms of a Persei, taken by Prof. Kiistner and 

 Dr. Zurhellen between .-Xugust, 1904, and March, 1906, 

 Herr F. Goos has derived values for the radial velocities 

 of the star during that period. Previous observers have 

 found that the variation of the velocity is small or non- 

 existent. 



In the present investigation Herr Goos made eight 

 settings, each way of the plate, on twelve iron lines which 

 are taken as standards, and found that the velocity, relative 

 to the sun, varied between —3-65 km. and o, the prob- 

 able error for each plate being +0-40 km. (Astroyiomische 

 Nachrichten, No. 4300, p. 50). 



A Catalogue of 1625 Southern Stars. — Vol. ii. of the 

 " Meridian Observations of the Perth Observatory (W. 

 Australia) " contains the results of the meridian observa- 

 tions of 1625 stars between 39° and 41° south declination. 

 As explained by Mr. Ernest Cooke, the director of the 

 observatory, in the introduction, these results form part 

 of the scheme undertaken by the Perth Observatory to 

 determine, from time to time, the accurate positions of 

 some 8000 stars lying in the zone 3i°-4i° S. declination. 

 The positions now given are reduced to the equinox of 

 igoo-o at the epoch of observation, and, when known, the 

 proper motions, for reduction to epoch, are also given. 



The Melbourne Observ.atorv. — Mr. Baracchi's report 

 of the work done at the Melbourne Observatory during the 

 period 1906 December i to 1908 April 30 shows that the 

 observatory is, apparently, now well established as a purely 

 astronomical institution, the meteorological work having 

 been transferred to the new Weather Bureau, under the 

 Commonwealth Government, from the end of 1907. 



The long-vacant post of chief assistant has now been 

 filled by Mr. J. M. Baldwin, an 1851 Exhibition scholar, 

 who has further qualified for the post by visiting and 

 working at a number of English, Continental, and 

 American observatories. 



Mr. Baracchi reports, concerning the astrographic chart 

 work, that, to April 30, 1908, 707 Sydney plates, con- 

 taining 430,468 stars, and 991 Melbourne plates, contain- 

 ing 318,025 stars, were completely measured. The report 

 concludes with a strong recommendation that, in accord- 

 ance with the suggestion of the Solar Union, supported 

 by the Royal Society, a solar physics observatory should 

 be founded in Australia, preferably at .Adelaide. 



SCIENTIFIC AID FOR THE BRITISH TENANT 



FARMER. 

 T^HE various agricultural colleges founded or subsidised 

 -'■ by the county councils take a wide view of theif 

 functions, and not' only give instruction in agriculture 10 

 young men wishing to take up this subject, but also carry 

 out tield experiments designed to instruct those who are 

 already farming, and who will not or cannot attend 

 lectures. The field experiments are not strictly in the 

 nature of research work, since they do not usually involve 

 any new principles ; they are not always arranged to give 

 all the results they might, but, taken as a whole, they 

 serve the very useful purpose of demonstrating to the 

 farmer certain facts which he ought to know, but often 

 does not, and of giving him opportunities of seeing for 

 himself the efTect of special manures on crops or of special 

 feeding stulTs on animals. 



The results of the field trials are published in pamphlet 

 form by the college or department concerned, and widely 

 distributed among the farming community. Recently the 

 Board of .■\griculture started a summary of these re- 

 ports in its journal, and the idea is a very useful one. 

 The South-Eastern .Agricultural College publishes its re- 

 ports in the form of an annual journal, while the 

 University of Cambridge has periodically brought out full 

 reports dealing with the whole of its experiments in the 

 counties. 



In the nature of the case, many of the reports issued 

 are of local rather than of general interest, and do not 

 call for any full treatment here, but a few instances may 

 be quoted to show the type of work being done. Experi- 

 ments at the University' College of Wales, Aberystwyth, 

 have been made to find out what ration will prove profit- 

 able for fattening bullocks. The fact that animals require 

 a tolerably large maintenance ration {i.e. that they eat a 

 fair amount of food without gaining in weight) renders 

 it necessary that fattening should be rapid, but the diffi- 

 culty then 'arises that a large ration gives proportionately 

 less' increase in weight than a small one. Up to a certain 

 point an increase in the ration is profitable ; beyond this 

 point the profit gradually decreases, and loss arises. Prof. 

 Jones has illustrated these facts very well in the report 

 before us. 



The Northumberland experiments deal with pasture 

 problems. It has been demonstrated that basic slag is 

 the most effective manure for economically improving the 

 heavy soils of Northumberland, and a mixture of basic 

 slag and a potash manure is best on the lighter soils. 

 It has also been shown that second, and even third, dress- 

 ings of slag are quite as effective as the first. The mange! 

 experiments have shown that nitrate of soda gives better 

 results than sulphate of ammonia, that slag is more 

 effective than superphosphate, that sulphate of potash 

 is better than the muriate, and that common salt much 

 increases the crop. Experiments on other crops are also 

 recorded. 



Rather dilTerent results were obtained in the Scotch 

 experiments on pastures summarised by Mr. Hendrick. 

 Basic slag led to an improvement, but not much, and 

 three or four years elapsed before sufficient return was 

 obtained to pay for the slag. However, the improvement 

 lasts, and can be seen six years afterwards, so that the 

 method is profitable. No other manure was found to give 

 profitable returns. This report gives analyses of the soils, 

 and is therefore much more interesting than those in 

 which soil analysis is ignored. 



The West of Scotland Agricultural College has issued 

 reports by Prof. Mc.Alpine. The experiments on varieties 

 of oats made during the years 1902-7 are summarised, and 

 the effect of manures is' discussed. Manuring has but 

 little influence on the kernel weight, and only very slightly 

 increases the proportion of kernel to husk. 



The Lancashire County Council experiments were de- 

 signed to test the relative value of limestone and of burnt 

 lime for improving pastures, and the conclusion is drawn 

 that limestone is the more effective, provided it contains 

 95 per cent, of calcium carbonate and is ground to a 

 sufficiently fine state. 



The farmer has not only to produce crops and beasts, 

 but to sell them, and success in one branch of his pro- 



NO. 2054, VOL. 80] 



