HARDWICKE'S SCIENCE-Q OS SIP. 



nebula;. 518 was perhaps due to magnesium oxide. 

 It was thought the new star was closely allied to 

 others, and was probably colder and older than them, 

 From February 1st a set of estimates of its brightness 

 on various dates up to the nth had been made. 

 There was a very marked increase in its brightness, 

 and it fell down to the fifth magnitude on the 

 Tuesday. He was fairly confident of its maximum of 

 brightness on the Sunday. The observations of bright- 

 ness tended to show a relationship more to a variable 

 star than to a "Nova" burning itself out within a 

 few weeks of its appearance. The most remarkable 

 feature about it was the 502 line being so near the 

 great nebula line. That had not been seen in spectra 

 of variable stars. 



At the last meeting of the Society of Marine 

 Engineers, a paper was read on " Initial Condensa- 

 tion," after which the fullowing propositions were put 

 before the meeting : I. That range of temperature 

 does not cause, but permits condensation ; 2. That 

 the increased initial condensation found with higher 

 rates of expansion is due to increased work, and not 

 to increased range of temperature ; 3. That initial 

 condensation may occur not only when steam is used 

 at full pressure throughout the stroke, but even when 

 no useful work is performed ; 4. That the lessened 

 initial condensation generally found with stage 

 expansion engines is largely due to reduced range 

 of temperature, but notwithstanding reduced range of 

 temperature a stage expansion engine may condense 

 as much steam as a single stage engine ; 5. That 

 conducting-cylinders do not of themselves cause 

 initial condensation, the actual cause being the dis- 

 appearance of heat and consequent liquefaction of 

 steam in the performance of work ; 6. That discord- 

 ant results are almost certain to arise when the 

 condensive surfaces are active up to their full capacity ; 

 7. That instead of it being necessary to consider why 

 initial condensation exists, it is often necessary to 

 enquire why it is not greater. 



We have received from Professor Prestwich his 

 admirable and suggestive paper illustrated with maps 

 and specimens " On the Primitive Characters of the 

 Flint Implements of the Chalk Plateau of Kent, with 

 Reference to the Question of their Glacial or Pre- 

 Glacial Age," with notes by Messrs. B. Harrison and 

 De Barri Crawshay. 



We are pleased to receive the fourth report of the 

 "Microscopical Society of Calcutta," which, owing 

 to the possession of an active president, and an 

 equally active secretary, J. Wood Mason Esq., and 

 W. J. Simmons, now commands attention. 



The increasing interest in natural history is best 

 shown by the new periodicals required to deal with 

 its manifold questions. We have to announce and 

 welcome the advent of another competitor for popular 



favour in "Natural Science," price Is. An admirably 

 printed and well got-up magazine, in which we are 

 glad to see the names of several esteemed contributors 

 of Science-Gossip appearing. 



We have received a pamphlet, beautifully printed 

 and tastefully got up, entitled, " A Review of the 

 work of the Leeuwenhoek Microscopical Club, Man- 

 chester, 1867-91." The title-page is illustrated with 

 a beautiful photograph of Leeuwenhoek, from the 

 engraved portrait by Anker Smith, in the 1800 

 edition of Leeuwenhoek's works, of Hoole, London. 



The " International Journal of Microscopy and 

 Natural History " for January is unusually interesting. 

 It is crowded with good matter, and has some ex- 

 cellent illustrations. 



One of the most important natural history associa- 

 tions in this country is the " Transactions of the 

 Yorkshire Naturalists' Union." Nothing more tho- 

 rough has ever been turned out by any society. The 

 parts deal with the botany, geology, climate, physical 

 geography, entomology, &c. , of the premier county, 

 in addition to which there is a separate part by Mr. 

 Robert Kidston on the Yorkshire carboniferous flora. 

 These parts are published by Taylor Brothers, Leeds. 



We beg to call attention to the following second- 

 hand scientific book catalogues, as very likely to 

 prove useful to our readers : — Messrs. Wesley's 

 No. 115 Catalogue of Works relating to Meteorology, 

 Physical Geography, and Aeronautics ; Messrs. Du- 

 lau's Catalogue of Works on Geology, 108 pages ; 

 and Mr. W. P. Collin's Monthly Catalogue of Books 

 on Science and Natural History. 



The last number of the "Journal of the New 

 Jersey Natural History Society" contains a useful 

 paper on the "Molluscs of the Atlantic Coast of the 

 United States South to Cape Hatteras," by Austin 

 C. Aggar. 



Baron Felder, formerly Burgomaster of Vienna, 

 has sold his great collection of butterflies to Lord 

 Rothschild for 5000/. The collection is said to be 

 destined for the British Museum. Baron Felder, 

 who is seventy-eight years old, has parted with it for 

 fear that otherwise after his death it would be broken 

 up. The price is considered very low. 



Mr. Ludwig Mond, the brilliant Swiss Chemist, 

 has not only discovered how to dispose of ordinary 

 coal smoke, but how to turn it into a highly profitable 

 commodity. The statement is that by burning 125 

 tons of coal, at a cost of 31/., and making full use of 

 it for steam raising purposes, he can at the same time 

 secure, by a simple process he has invented, four tons 

 of sulphate of ammonia from the smoke produced by 

 the coal. The money value of this will be 48/. 



An American astronomer, Professor Chandler, of 

 Harvard, has started the theory that the variable star 



