HARDWICKE'S SCIENCE-GOSSIP. 



89 



Spectacles " (illustrated) by P. J. Edmunds ; " Flying 

 Machine Memoranda" (illustrated), by Lawrence 

 Hargrave ; " Irrigation in its Relation to the Pastoral 

 Industry of New South Wales," by H. G. M'Kinney 

 (with two maps); " Eruptive Rocks of New Zealand " 

 (illustrated), by Professor F. W. Hutton. 



Mr. W. A. Gain writes us as follows : " I have 

 just seen a very striking example of the synthesis of 

 light. Going to the post-office, which is in a druggist's 

 shop, I placed on the edge of the usual pigeon-hole, 

 in payment for stamps, what I supposed to be a 

 sovereign ; behold, a shilling instead ! I took up the 

 coin, wondering whether or not I had paid away the 

 sovereign by mistake and placed a shilling in its place, 

 but no sooner had I taken the piece up than there was 

 the sovereign as ruddy as need be. Among the bottles 

 in the window is one of a blue colour, the light passing 

 through this fell just within the pigeon-hole, scarcely 

 showing on the dark-coloured counter. When the 

 bright coin was laid here this colour mingled with the 

 red and yellow of the gold, producing white reflected 

 light, or rather that very pale shade of gray which 

 silver possesses. The clerk thought it necessary to 

 test the coin which had produced such strange results, 

 thus showing that the phenomonon had not been 

 observed previously." 



A very successful photographic exhibition was 

 held at the Crystal Palace from March nth to 29th, 

 and certainly did great credit to those who had the 

 management of it. 



Messrs. R. & J. Beck have brought out a new 

 camera which they call the " Pecrops." The main 

 advantages of this camera are, that whilst being very 

 compact and portable, it is at the same time perfectly 

 rigid, and also possesses great simplicity of ad- 

 justment. 



H. GEORG, of Basle, sends us his catalogue of 

 Botanical works in all languages. There is a 

 wonderfully good variety of books, and the prices 

 asked are moderate. 



Mr. S. E. Peal, of Calcutta, sends a copy of his 

 paper, " A Theory of Lunar Surfacing by Glaciation," 

 in which he gives it as his idea that the moon is 

 covered all over, from the poles to the equator, with 

 a cap of ice. The idea is exceedingly well worked 

 out, and the paper is well worth reading. 



Nos. 13 and 14 of the "Naturalists' Guide," 

 published by Mr. S. L. Mosley, Beaumont Park 

 Museum, contain a sort of vade mecitm of butterflies, 

 giving the distinctive features of all British species. 

 This should be very useful, especially to beginners, 

 and the price is most moderate, only sixpence. 



The Photographer's Diary and Desk-Book for 1S90, 

 published at the office of the " Camera," whose editor 



has compiled it, is a most useful and valuable book 

 for photographers. The preliminary part gives good 

 hints and formula printed in a type that can be easily 

 read by the light in photographic dark room. It also 

 contains a photograph and biographical sketch of Mr. 

 Andrew Pringle, president of the photographic con- 

 vention of the United Kingdom. The diary is on 

 good paper, and is interleaved with blotting-paper 

 throughout. 



Mr. W. K. Mann, of 10 Wellington Terrace, 

 Clifton, sends us a copy of his handy little Catalogue 

 for 1890. In it a natural history student will find 

 mention made of everything useful to him in his 

 studies, and moreover at very moderate prices. 



Professor Ville has brought out a new manure 

 for vineyards and vines. It consists of a mixture of 

 phosphate of chalk, carbonate of refined potash, and 

 sulphate of chalk, which, if placed round vine-growths, 

 will enable them to defy the onslaughts of the phyl- 

 loxera. Nitrate of potash may be used instead of 

 carbonate, which is dear ; but, in order to make the 

 manure efficacious in its results, the vines should be 

 fumigated in the late autumn or in January and 

 February. M. Ville has tried his experiments on 

 French vines at Vincennes, but he is of opinion that 

 his manure will be of equal use in America or 

 Australia. He furthermore predicts that his chemical 

 concoction will not only destroy the phylloxera, but 

 lead to an abundance of grapes, which are nowadays 

 so scarce in France that Spanish and Italian vines of 

 inferior quality have to be drawn upon for the 

 fabrication of the French wines. 



Rev. J. S. St. John will shortly bring out " Larvae 

 Collecting and Breeding : a Hand-Book to the Larvae 

 of the British Macro-Lepidoptera and their Food- 

 Plants." The book promises to be a very useful one, 

 and our entomological readers will show their 

 appreciation of the trouble taken by Mr. St. John to 

 make the book as perfect as possible by becoming 

 subscribers. The subscription price will be one 

 shilling and sixpence, to non-subscribers the price 

 will be two shillings. 



At the last meeting of the Cardiganshire County 

 Council Dr. Lloyd Snape, of the University College 

 of Wales, was unanimously appointed county analyst. 



Some diligent statistician has got up the following 

 details concerning the recently opened Forth Bridge. 

 Upwards of 21,000 tons of cement, 707,000 cubic 

 feet of granite, and 117,000 cubic yards of masonry 

 were employed in the foundations and piers of the 

 Forth Bridge, and the weight of steel used in the 

 construction of the superstructure was 51,000 tons. 

 The rivets employed in the Forth Bridge would, if 

 laid end to end, cover about 380 miles in length ; 

 the number of rivet holes drilled have been over 



