268 



NATURE 



\Aug. I, 1875 



extraordinary amount of energy (theoretically capable of 

 exertin<T ^^ = 14-5 horse-power) is called forth by the 

 moderate differential temperature of 212 - 102 36 = 

 109-44.° F. Now, let us compare the energy of 623 thermal 

 units per minute to that produced by the radiation of a 

 metallic surface coated with Ump black, and maintained 

 at a temperature of 212", within an enclosure of 102'. 

 Actual trial shows that under these conditions, the radiant 

 energy of a blackened plate composed of copper, contain- 

 ing \ii\ sq. inches, scarcely reaches 6 thermal units per 

 mfnute. Our experiment has therefore established the 

 fact, incidentally, that under the stated conditions, a pla'.e 

 of wrought copper two inches in thickness is capable o! 

 transmitting by conduction from one side to the other, 

 in a given time, an amount of mechanical energy more 

 than "100 times greater than the mechanical energy de- 

 veloped by the radiation of the same plate during an 

 equal interval of time. 



Table I. — Cotper Column 



Table II.— Mercurial Column 



J. Ericsson 



NOTES 



The voluminous correspondence connecterl with the man.ii,'e- 

 ment of Ke-.v Clardens, printed by order of Parliament, was 

 is.?ued at the close ol last week. In the debate in the House of 

 Lords on Monday, introduced by Lord Derby, the essential 

 points of the controversy wore hardly touched ; and pending ihe 

 debate in the House of Commons on Sir John Lubbock's motion, 

 which was not reached on Tuesday evening, it is obviously pre- 



mature to enter into the various discussions which are prompted 

 by the contents of the Parliamentary papers. 



The choice of a foreign correspondent of the YxfUzxAcacicink dcs 

 Scicnccs\\3.i resulted in the defeat of Mr. Darwin and the election 

 of M. Loewen, of Stockholm, who receixed 32 votes, against 15 

 given to the English naturalist. The. discussion had extended 

 over three long sittings in secret committee, the leader of the 

 advocates of Mr. Darwin's claim being again his opponent in 

 controversy, M. de Quatrefages, while M. Emile Blanchard led 

 the opposition. A correspondent of Les Moiidcs, an eminent 

 member of the Academy, in commenting on the result, states 

 that not one of those who voted for Mr. Darwin shared his 

 pliilosophical doctrines, and not one of those who opposed his 

 candidature alleged as their motive the error or danger of his 

 doctrines. " What has closed the door of the Academy to Mr. 

 Darwin is that the science of those of his books which have made 

 his chief title to fame — the 'Origin of Species,' and still more 

 the ' Descent of Man ' — is not science, but a mass of assertions 

 and absolutely gratuitous hypotheses, often evidently fallacious. 

 This kind of publication and these theories are a bad example, 

 which a body that respects itself cannot encourage." 



The subject of Prof. W. K. Clifford's discourse at the ensu- 

 ing meeting of the British Association will be, " The Aims 

 and Instruments of Scientific Thought." Mr. \V. Spottiswoodc 

 will deliver a lecture to working men, on " .Some Properties of 

 Light, Suuihine, Sea, and Sky." 



The Iron and Steel Institute will hold its nc.vt meeting in 

 Glasgow, under the presidency of Mr. Henry Bessemer. Tlie 

 reception room will be in the Corporation Galleries, Sauchiehall 

 Street. The general meetings will be held in the Lecture Hall, 

 Corporation Galleries, Sauchiehall Street, asunder: — Tuesday, 

 Aug. 6, 1.30 P.M., Election of Members, Report of Council to 

 be presented. Papers; Wednesday, Aug. 7, 10.30 A.M., I'^eading 

 and Discussion of Papers; Thursday, Aug. 8, I0 30.\. M., Reading 

 and Discussion of Papers. A room will be provided in the Cor- 

 poration Galleries for the exhibition of objects of interest to the 

 trade, either from the neighbourhood of Glasgow or elsewhere. 

 The business proceedings will terminate about 3 o'clock on Tues- 

 day, and it is proposed that members should devote the remain- 

 der of the day to visiting the iron and other works in the 

 neighbourhood of Glasgow. A list of these works will be given 

 in the detailed programme to be distributed at the meeting ; and 

 a .sketch map of the district will also be ready at the same time. 

 On Wednesday, immediately a'ter the conclusion of the business 

 meeting, a special train will be provided to convey the members 

 to Coatbridge and Monkland, where the Gartsherrie, Suminer- 

 lee, Langloan, Coatbridge, Malleable, and Monkland Iron 

 Works will be inspected. On Thursday, after the conclusion of 

 the general meeting in Glasgow, a special train will be arranged 

 for the Motherwell district, and for tlie inspection of the iron 

 works in that locality. On Thursday evening, at 7 o'clock, the 

 members will be entertained at dinner, in the Corporation Gal- 

 leries, Glasgow, by the Local Reception Committee. On Friday 

 an excursion will be made down the Clyde, for the purpose of 

 seeing the industrial features connected with the river. The ex- 

 cursion will also be prolonged to the head of Loch Long, the 

 return being by Loch Lomond to Balloch, and thence by train 

 to Glasgow. Luncheon will be provided at Tarbet. The fol- 

 lowing papers have been already promised : — " On the Geologi- 

 cal Features of the Iron and Coal Districts of Scotland," by Mr. 

 James Geikie, F.G.S., of the Geological Survey of Scotland ; 

 " On the Rise and Progress of the Iron Trade in ScoUand," by 

 Mr Jno. Mayer, F.C.S., Glasgow; " On the Differential Clutch 

 for Reversing Mills," by Mr. R. D. Napier, Glasgo«r; "On 

 t\eversing of Rolling Mills," by Mr. Graham Stevenson Airdrie; 

 " On an improved form of Squeezer for Blooms produced in 



