558 



NA TURE 



[April 15, 1886 



ment. There is, in fact, strong presumptive evidence 

 that she became his wife nine years previous to his 

 unlooked-for death in 1715. The position, it is true, was 

 never expHcitly claimed by or for her ; but silence might 

 easily have been imposed by the inferiority of her social 

 position. At any rate, a letter written by Newton to his 

 kinsman. Sir John Newton, May 23, 1715, admits of but 

 one interpretation. It includes the following sentence : — 

 " The concern I am in for the loss of my Lord Halifax, 

 and the circumstances in which I stand related to his 

 family, will not suffer me to go abroad until his funeral is 

 over." No "circumstances" existed which could possibly 

 explain this allusion save one — that of a marriage between 

 the deceased nobleman and the writer's niece. The words 

 are used with no purpose of disclosure ; they treat the 

 fact they bear witness to as a known and indisputable one 

 — known, that is, to an inner circle, where Catherine 

 Barton moved all her life with the respect due to an un- 

 blemished character. Handsomely provided for by the 

 will of Lord Halifax, she married, in August 1717, John 

 Conduit, M.P., Newton's subordinate, and afterwards his 

 successor at the Mint, and died in 1739, leaving an only 

 daughter, ancestress of the present Earl of Portsmouth. 

 A considerable amount of elucidatory information 

 regarding the marriage-laws and social usages of the 

 last century adds to the value of t'je little work edited by 

 Mrs. De Morgan. 



Numerical Examples in Heat. By R. E. Day, M.A. 



(London: Longmans, Green, and Co., 1885.) 

 This is not merely a collection of numerical examination 

 questions with the answers attached, but a well-arranged 

 series of problems grouped under twenty-five heads, each 

 beginning with simple questions, which increase in com- 

 plexity. At the first introduction of every kind of question 

 the answer is worked out in full, with a sufficient ex- 

 planation to show the meaning of the operations. Other 

 questions are given with their answers, but without the 

 process of solution. 



LETTERS TO THE EDITOR 



\7 he Editor does not holdhimself i-esponsibh for opinions expressul 

 bv his correspondents. Neither can he undertake to return, 

 or to correspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communications. 

 [ The Editor urgently requests correspondents to keep their letters 

 as sriort as possible. The pressure on his space is so great 

 that it is impossible otherzuise to insure the appearance even 

 of communication s contain inginlerestivg and nojjel fads.] 

 Note on Sonnet to Pritchard 

 In the general theory of algebraical forms there are two modes 

 of defining an Invariant or Reciprocant. In the one mode 

 either of them is regarded as subject to satisfy a partial differ- 

 ential ei]HOtion~m the other as subject to extinction under the 

 action of a partial -differential operator. Of course the difference 

 between these two modes is one of presentation merely, and not 

 of substance. Nevertheless it was interesting to me to observe 

 that the very same rival concepts of equality and extinction lie 

 at the root of the admirable investigations simultaneously carried 

 on by Prof Pickering at Harvard (who works by equation of 

 light), and Prof. Pritchard at Oxford (who works by the method 

 of extinctio:i), which have earned for each of them the distinc- 

 tion of the award of the gold medal of the Royal Astronomical 

 Society. I say the gold medal, because the medal to each is to 

 be regarded in a transcendental sense as only one to both. 



This_ reflection added to the sentiments of regard which I 

 entertain towards my Savilian colleague caused me to write the 

 sonnet in his praise, which you have done me the honour to 

 insert in Nature (April i, p. 516), in which, owing to my own 

 inadvertence the words name and praise have got interchanged. 

 Being desirous that this tribute of unaffected admiration towards 

 the subject of it sliould be affected with as few blemishes as are 

 compatible with the feible versificatory powers of its author, I 

 request to be allowed to say that the first and last lines should 

 read — 



Piitchaid! thy name is lifted to the skies, 

 and 



Thy praise shall flourish in immortal song, 



respectively. Also that the third and fourth lines should run 



thus — 



To note each ray that gilds the hem of Night 

 Or eye her jewelhd brow with keen surmise. 



At the dinner of the Fellows of the Royal Astronomical 

 .Society on the evening of the public presentation of the Medal 

 to Prof. Pritchard, the sonnet was recited by its author at the 

 desire of the Astronomer- Royal, who presided on the occasion. 

 J. J. Sylvester, 

 Savilian Professor of Geometry in the University of 

 Oxford ; and Author of "The Laws of Verse " 



Fishery Board of Scotland 



Your leading article of the ist instant, headed "A Fishery 

 Board for England," contains several inaccuracies with regard 

 to the Fishery Board of Scotland which it appears desirable to 

 correct. 



(i) " If a Fishery Board is useful and valuable, it is a surpris- 

 ing fact that Ireland and Scotland have long enjoyed an institu- 

 tion which is wanting in England." 



The present Fishery Board for Scotland was constituted only 

 in 1S82. Prior to that date there was a Board of Fisheries 

 which, from its origin in iSo8 until 1S20, confined its attention 

 to the curing and branding of herrings, and to collecting statistics 

 of the quantities of herrings landed and exported. From 1820 

 to 1881 statistics of the cod and ling cured were also prepared. 

 This Board of Fisheries having charge of all the fisheries around 

 the coast of Britain, appointed officers at the chief Scottish and 

 English fishing ports, two of whom were stationed in London, 

 from which in the beginning of the centuiy large consignments 

 of herring were sent to the Continent. In course of time the 

 number of herrings cured at the English stations became so small 

 that in 1850 the English Fishery officers were dismissed. In 

 fact, the old Fishery Board existed chiefly in order to collect 

 statistics of cured fish and to superintend the curing and 

 branding of herrings. It will be understood how exclusively 

 attention has been devoted to these objects when it is men- 

 tioned that even now the Fishery officers must be practical 

 coopers. 



(2) " The Commission for the Investigation of the German 

 Seas is composed of distinguished men who are students and 

 teachers of biology or physics. In Norway and Holland the 

 same thing occurs." 



We believe it is a fact that neither the Norwegian nor the 

 Dutch Government has yet instituted Fish Commissions. 



(3) " A large number of matters connected with the fisheries 

 have not yet begun to receive attention even in Scotland." 



It was only in 1S83 that the Scottish Fishery Board obtained 

 from the Government a >um of 300'. for studying the life history, 

 &c., of the food-fishes, and the total sum received up to the end 

 of last month was only 2800/. When it is remembered that a 

 sum of 10,000/. has been required to found the laboratory of the 

 Marine Biological Association, it can scarcely be deemed a matter 

 of surprise that many topics of interest and importance have not 

 received from the Scottish Fishery Board that degree of attention 

 which they deserve. 



(4) "The spawn of the sprat is still entirely unknown." 



Mr. Duncan Matthews, of the University of Edinburgh 

 Zoological Laboratory, in his " Report on the Sprat Fishing 

 during the Winter of 1S83-84, " published in the Report of the 

 Fishery Board for Scotland for 1S83, describes and figures the 

 " spawn " of the sprat. 



(5) "The Scottish Fishery Board is about to try an extensive 

 experiment with regard to beam-trawling, prohibiting that 

 method of fishing in certain defined areas. The experiment is 

 worth trying, even at the cost of temporary inconvenience to 

 the fishery industry. But in order to render such an experiment 

 fruitful, it would be necessary to make a detailed and exact 

 investigation of the areas selected. It is doubtful whether the 

 organisation of the scientific department of the Scottish Board 

 is yet in a position to make this investigation in a sufficiently 

 complete manner." 



Seeing that he appears to speak as one having authority, an d 

 not as the scribes, it is gratifying to note that the writer o f 

 your article deems " the experiment worth trying." We have only 



