46 



Hope, and had there secured and brought home the most 

 astounding amount of both useful and even super-excellent 

 astronomical observations that ever one man made in twelve 

 months, — there was no apparent reason why he should not at 

 once have been allowed to step straight into this new Observa- 

 tory appointment, and commence its laborious duties forthwith. 

 But that was not to be ; for he was privately informed that he 

 must first and preliminarily be appointed a Professor in the 

 University of Edinburgh. He started at and resisted the idea ; 

 he said he did not want to be a Professor, and would not be 

 one ; it was an occupation wholly foreign to his tastes, and 

 entirely incompatible with the full and conscientious devotion of 

 himself to being a working astronomer within the Observatory. 

 Pressure, however, of powerful friends was brought to bear upon 

 him ; and he was made to understand that Government could 

 not, or would not, whatever the secret reason, create and set 

 agoing the new appointment for the Observatory on the Gallon 

 Hill, 'of " Astronomer Royal for Scotland," without first con- 

 necting it with a certain old and shameful sinecure in the 

 University of Edinburgh, called the Professorship of Practical 

 Astronomy. 



He was indeed assured that he would, and should, never be 

 called on to lecture in the Professorship ; that it was a mere 

 name and nothing more ; and his form of appointment to the 

 strangely and unnaturally duplex post of the old Professorship 

 and the new Astronomer Royalship, was made out in words 

 assigning clearly enough the work in the Observatory, of " with 

 zeal and diligence making observations for the extension and 

 improvement of astronomy, geography, and navigation, and 

 other branches of science connected therewith," to be his only 

 circle of duties and his only claim to salary, viz. 300/. per 

 annum. But then how were those promises fulfilled ; or rather, 

 how were they neglected and overborne when the multitudinous 

 heads of the great educational University of Edinburgh had once 

 got poor Thomas Henderson, the first Astronomer Royal for 

 Scotland, safe within their thrall as being also a Professor before 

 them ? 



Why thus : they immediately began treading on his toes from 

 every side ; and with the most magnificent disregard that he had 

 anything worthy of notice to do in the Observatory, they forced 

 on his attention, both in season and out of it, "that while they 

 were working so hard in the great educational hive, he was a 

 mere drone, and yet was in receipt of a salary of 3chd/. per 

 annum, an absolutely larger salary than any of themselves who 

 bore the brunt and burden of the tuition of all the students." 

 For the complainers, be it remarked, left out of view, that if 

 their incomes did not mount up to 300/. in the shape of salaries, 

 it was because they came to them chiefly in the form of students' 

 fees ; and in that phase sometimes reached 1,000/., 1,300/., and 

 even 1,600/. per annum. 



But this difference the teaching Professors cou^d not see ; 

 and so, if, as they knew perfectly well, there were no students 

 applying for Practical Astronomy Lectures, they determined that 

 the Practical Astronomy Professor should still be educationally 

 utilised, and as an assistant to other Professors, if not as a 

 Professor on his own account. Wherefore Thomas Henderson 

 was talked at, and talked at, until for one winter he was prevailed 

 on to give lectures in the University to the Mathematical Class 

 during the illness of its Professor. Then he was induced to take 

 up the onerous position of Secretary to certain University trusts. 

 And then, while that was still going on, he was over-persuaded 

 into giving lectures for the then Professor of Natural Philosophy 

 during one of his retirements ; and then, — why, then, Thomas 

 Henderson, who was all this time struggling almost superhumanly 

 by night and by day to keep up his observations as Astronomer 

 Royal for Scotland in the Royal Observatory, Edinburgh, — why, 

 then — he died ! Died too at the early age of forty-six years, and 

 Scotland has not seen his like either before or since ; for he was 

 in fact the one and only high-class and complete practical as- 

 tronomer whom his country and his nation have ever produced ; 

 and yet he was hurried to a premature grave, trampled on by an 

 unsympathising educational University. 



Of my own troubles in trying to fill this truly great man's 

 place, I could tell a vast deal, but would rather merely refer to 

 my last official Report to the Government-appointed Board 

 ■ of Visitors of the Royal Observatory, Edinburgh ; wherein, 

 after showing forth the recent attempts of the University authori- 

 ties actually to *' transfer " from the Astronomer Royalship of 

 Scotland the tvkole of the salary originally appointed to that 

 office by the Crown, and take it over to their own studentless 

 Professorship, I have finally besought the Board to apply to 



NATURE [Nov. i8, 1875 



Government to separate the two offices absolutely and for 

 ever. 



Most heartily convinced therefore must I be of the positive 

 wisdom of those weighty words of Colonel Strange, alluded to 

 in your p. 429 ; wherein, after stating his belief that there 

 should be a Minister of Science, to look after the interests of 

 institutions for the promotion of science, as entirely apart from any 

 or all the institutions for education, whether in science or any- 

 thing else, that most sage and experienced officer goes on to 

 say : — 



" That he considers education to be quite a different thing 

 from national research, and that they should be kept as distinct 

 as possii)le ; and that one great evil now existing is the mixing 

 up of those two things." 



PiAzzi Smyth, 

 Professor, and Astronomer Royal for Scotland 



Royal Observatory, Edinburgh 



Ericsson's Researches on the Sun 



In your interesting journal (vol. xii. p. 519) I see a descrip- 

 tion of an experiment by Capt. Ericsson, intended to measure 

 the difference of temperature between the centre and the edge 

 of the sun. I do not intend to make here any criticism on this 

 experiment, but only to make some remarks on the final conclu- 

 sions. 



We must first distinguish two kinds of results — one directly 

 given by the observation, the other by calculation. 



In the first, we agree as far as is possible in considering the 

 different methods of solving this question. He finds, indeed, 

 that the intensity near the edge is 0-638 of that of the centre, the 

 outer zone being in the mean line 49" distant from the edge, and 

 consequently large, 98" = i' 38". On my experimenting on a 

 small area not exceeding one minute square, and distant from the 

 centre 14' -920 = 14' 55" '2 (and consequently distant in Sep- 

 tember from the edge 62"), I found 0-5586. The difference is 

 indeed not very considerable, being 0-0794. Now Plana has 

 shown, in the Astron. Nachrichten, No. 813, that such a small 

 difference may lead to a very considerable difference in the value 

 of the absorption. 



The value of the solar atmospherical absorption, according to 

 Mr. Ericsson, cannot be greater than 0-144 o^ the radiant heat 

 emanating from the photosphere (page 520), and he then quotes 

 my results, in which it is stated that 0-88 is absorbed by the 

 whole atmosphere. He proceeds to remark: "It is unneces- 

 sary to criticise these figures presented by the Roman astronomer, 

 as a cursory inspection of our table and diagrams is sufficient to 

 show the fallacy of his computations." 



I beg leave to observe that the fallacies are not only my own, 

 but those of Laplace and Plana as well, who from the numbers 

 of Bouguer's have arrived at a conclusion very similar to my own. 

 The fallacy, I think, is rather in Mr. Ericsson's method of calcu- 

 lating. In a problem of so great difficulty, and where the great 

 analysts have^ established very complicated formulae, he makes 

 use only of some very simple proportions, which are by no 

 means justified, and with these he thinks his conclusion is very 

 plain ! I regret to say that such a method of computing in this 

 case cannot be admitted, and consequently we are justified in 

 attributing the difference of the results, not to the fallacy of our 

 computation, but to the fallacy of those proportions assumed by 

 Mr. Ericsson, unless he, or any competent mathematician, be 

 able to show some great error in the formulae of Laplace and of 

 Plana. 



Several objections besides may be made to his manner of 

 experimenting, but of that on another occasion. In applying the 

 numbers of Mr. Ericsson to the formulae of Laplace and Plana, 

 the result will be found to be not very different from mine. But 

 at present I have no time to discuss these and other calculations, 

 and also I wait for the new experiments which he has promised. 

 I will only add that I do not share his opinion that the lenses 

 and telescopes introduced in these researches by me do not give 

 reliable results. P. A. Secchi, 



Rome, Oct. 28 Director of the Roman Observatory 



Sir G. B. Airy and the National Standards 



In Nature vol. xiii. p. 35, the following statement occurs : — 



" In the civic speeches which accompanied the ceremony [of 



conferring the Freedom of the City of London], great stress was 



laid on Sir G. B. Airy's services in coimection with the Metric 



Standards. " 



I 



