;«4 



NATURE 



[January 16, 19 19 



igreement with his timely protest 

 against sing of ;i chair of chemistrj at 



King's College, London, at the "princelj salary" of 



. '.car. 



Prof. Armstrong hopes that the profession will make 

 no response. There is, however, little doubi tliat 

 there will be a quite substantial competition for the 

 post among the best of our chemical lecturers. The 

 ii ason is, of course, that 600/. does appear to the 

 university lecturer a princely plum worth scrambling 

 for; it means for him at one jump an increase to 

 from two to three times his present salary, and he 

 knows that as the number of such relatively well- 

 paid posts is much smaller than the number of lec- 

 turers, it is his dutv to his dependents to leave no 

 chance untried. 



That I am not drawing an exaggerated picture will 

 be evident from a consideration of the following 

 average salaries of non-professorial teach ts, calculated 

 from data which I have before me, derived from 

 fifteen universities and university colleges: — 



i-5 

 6-10 



"-15 

 16-20 



30 

 1 1 



4 



Average salai 



2 39 



21-25 ••• ••• " 20 3 



26-30 4 297 



3 '"35 3 2 73 



The professorial view of a salary of 6ooL is another 

 matter. What the gentleman appointed to the chair 

 at King's College will think a few years hence is 

 also another matter. 



The preliminary to any effort to maintain a reason- 

 able professorial scale of remuneration by the absten- 

 tion of lecturers from competing for what are for 

 them really well-paid posts is to ensure the lecturer a 

 reasonable living wage. And this, too, is Prof. Arm- 

 strong's solution put in rather different form. Why 

 not call the post a lectureship? A glance at the above 

 table will show that to abstain from competing for a 

 600L post, simply because it is called a professorship, 

 in, say, one's twelfth year of service, is a risk too 

 grave to be taken. 



The Scottish lecturers have been recently granted a 

 graded scale rising to 750L This is in line with the 

 revised scheme of remuneration for the scientific staff 

 of the National Physical Laboratory, as follows : — 



Mil 



Superintendents .., 

 Principal assistants 

 Senior assistants ... 

 Assistants, I. 

 Assistants, II. 

 Junior assistants ... 



Max. 



£ 

 1000 



£ £ 



800 50 



650 2 S 75° 

 500 25 600 



35° 2 ° 45° 

 250 20 350 



175 J 5 23S 



In regard to abstention, another and very vital diffi- 

 cult\ arises. How is a lecturer to know what his col- 

 leagues will do? lie may by abstaining cut his own 

 throat without achieving any reform. Both professors 

 and lecturers arc in a dilemma. What is to be done? 



The answer is perfectly clear. We universitv 

 teachers should have an association which would do 

 for us, or enable us to do for ourselves, what the 

 Medical Association does for the doctors. This is a 

 perfectly practical suggestion. It may be taken as 

 certain that in the course of evolution such an asso- 

 ciation is destined to come. What is to prevent it 

 from being an accomplished fact within six months 

 from to-day? U. Douglas Laurie. 



University College of Wall -. Abervstwvth. 

 January 0. 



NO. 2^68. VOL. I02 I 



Airy and the Figure of the Earth. 



I SHOULD be very much obliged if any reader of 

 Nati RE would kindly give me an answer to the fol- 

 low ing question : — 



In a note on p. 371 of the second volume of the 

 treatise cm " Natural Philosophy," by Thomson and 

 Tait, I read : "Airy has estimated 24 ft. as the greatest 

 deviation of the bounding surface from the true 

 ellipsoid" Where did Airy give the result 24 ft? 



Darwin ("Scientific Papers," vol. hi., p. 78) wiit.s : 

 "Airy further concluded that the earth's surface must 

 be depressed below the level of the true ellipsoid in 

 middle latitudes. He gave no numerical estimate of 

 this depression, but expressed the opinion that it must 

 be very small." 



It is curious to remark that Todhunter, in his 

 " History of the Theory of Attraction, etc.," made no 

 mention of the paper by Airy on the figure of the earth 

 printed in the third part of the Philosophical Trans- 

 actions of the Royal Society for the year 182b, which 

 is the paper alluded to in the above quotation from 

 Darwin. OrTAVio Z.wotti Bianco 



(Docent of Geodesy in the R. University of 

 Turin!. 



Torino (Italy), Via della Rocca 28, 

 November 28, [918. 



I have carefully examined the curious points raised 

 by Sig. Bianco, and cannot find any satisfactory 

 answer to the questions asked. 



Thomson and Tait's footnote, in which it is stated 

 that Airy "estimated 24 ft. as the greatest deviation 

 of the bounding surface from the true ellipsoid," occurs 

 also in the first edition of the "Natural Philosophy." 

 It is true, in a sense, that Airy gave in his pub- 

 lished paper no distinct numerical estimate of this 

 deviation. Nevertheless, in his discussion of Sabine's 

 pendulum observations, he compared the coefficients 

 of certain terms with the corresponding values in terms 

 of e and A as given in his theoretical formula. The 

 value of A so found (see Phil. Trans., vol. cxvi., 

 p. 366) is 0-000064. I' 1 latitude 45 the deviation is 

 flAx|xi, and this is 334 ft., and not 24 ft., as 

 Thomson and Tait give it. 



The only other possible explanation is that Airy had 

 communicated a later estimate privately to Thomson, 

 for it is quite conceivable that Airy may have made 

 an estimate which he never published. I can find 

 no other publication of his in which this estimate 

 is given or from which it may be derived. 



In the davs in which Thomson and Tait were 

 writing their book — i.e. in the "sixties" of last cen- 

 tury — Thomson was much interested in the figure of 

 the earth, and he was almost certain to be in touch 

 with Airy. 



Personally, I never thought of questioning the 

 accuracv of the footnote. Sir George Darwin read the 

 proof-sheets of the second edition and wrote a number 

 of sections. He let it pass, although in his own 

 writings he savs that Airy gave no estimate. This, 

 however, is not quite correct. 



I can throw no further light on it. Possibly a 

 better series of pendulum observations than those 

 given by Sabine might lead to the result 24 ft. 

 But that is rather a wild speculation. 



C. G. Knott. 



Some Temperature Anomalies. 



I have often noticed the anomalies of temperature 



to which Mr. Harries directs attention in Nature of 



Januarv 9, and have sometimes been inclined to 



ascribe the high temperature in the -east to air that 



