io6 



NA TURE 



[November 25, 1909 



point of convergence of the trade wind, which in summer 

 is about 8° N. At a greater height the zone of winds 

 with a southerly component, forming the anti-trade, was 

 met with ; on approaching the equator this zone was 

 found at a lower altitude, being at about iSoo metres near 

 Cape Verde Islands. Temperature first decreased rapidly 

 with height ; above 500-600 metres a zone with slight 

 decrease, and extending with or without inversion up to 

 about 2500 metres, was met with, as previously pointed 

 out by Prof. Hergesell. In the neighbourhood of the anti- 

 trade the temperature commenced to decrease regularly up 

 to 14 or 15 kilometres. Above this height the so-called 

 isothermal zone was found, the existence of which was 

 pointed out by the author some years ago. These 

 characteristics are analogous to those observed in temperate 

 regions during a well-formed area of high barometrical 

 pressure. 



The Bausch and Lomb Optical Company, 19 Thavies 

 Inn, Holborn Circus, has published a new microscope chart 

 for use in laboratories where instruction is given in prac- 

 tical microscopy. This appears to be becoming a recog- 

 nised method of advertising with Continental and American 

 microscope makers, although we are not aware that any 

 English firm has yet issued such a chart. It is extremely 

 well got-up, shows the mechanical and optical essentials 

 of the instrument very well, as well as diagramatically 

 representing the direction and path of the rays of light 

 which pass from the illuminant and go to form the micro- 

 scopic image. The chart may be obtained gratis by any 

 •college or medical institution, and it can be used with 

 advantage wherever work is done with the microscope. 



Messrs. Ernest Leitz, of Wetzlar, Germany, and 

 <) O.'iford Street, VV., have issued a new edition of their 

 catalogue of microscopes, and a separate one of micro- 

 scopical accessories. It is interesting to note that Messrs. 

 Leitz are always more nearly approaching the English 

 type of stand in their new model microscopes ; in one at 

 least of their recent instruments the English type has 

 been entirely adopted. They are also bringing out new 

 achromatic condensers, and providing much more efficient 

 arrangements for the centration of these on the micro- 

 scope. Their new reflecting condenser for dark-ground 

 illumination, which differs from any other in that it 

 ■consists of spherical reflecting surfaces, is among the best 

 to be obtained. They claim for it that not only is its 

 correction of the highest order, but that the amount of 

 light that actually reaches the object is greater than in 

 any other appliance of a similar nature. In general, the 

 •character of the productions of this firm is such that 

 •workers who wish to obtain instruments for microscopy 

 may well give attention to these new catalogues. 



In the course of his address to the Northern Architec- 

 tural Association, an abstract of which appears in the 

 Builder of November 13, the president, Mr. G. T. Brown, 

 dealt with the question of architectural copyright. The 

 law, as it stands at present, is that the client may demand, 

 not only the whole of the drawings and specifications, but 

 also the studies and detailed calculations, and there is 

 nothing to prevent his making what use of them he 

 pleases. Other buildings may even be carried out by their 

 aid without the architect receiving any compensation for 

 them whatever. Means are taken in other countries to 

 protect the interests of the architectural profession, and 

 the hope is expressed that a Government Bill will be 

 introduced at an early date to deal with the matter. 



An interesting article on New York City bridges, by 

 Mr. T. Kennard Thomson, appears in the Engineering 

 NO. 2091, VOL. 82] 



Magazine for October. Among other bridges illustrated 

 and described is the Williamsburg Bridge, which is claimed 

 to be the most rigid long-span suspension bridge ever 

 built. The main span is 1596 feet, and the total length of 

 the bridge is 7250 feet, nearly one and a half miles. The 

 stiffening trusses are about 40 feet deep ; the four main 

 cables are each made up of thirty-seven strands, each 

 strand containing 208 wires, making a total of 31,784 

 wires in the four cables. Expansion and contraction and 

 the effect of the live load produce a deflection at the centre 

 of the span of 6 feet 9 inches, and yet this is a very 

 rigid suspension bridge. The Brooklyn suspension bridge 

 has a river span of 1595 feet, the total length being 

 6000 feet. Its centre rises and falls about 9 feet each 

 way (18 feet in all), partly owing to the loading and 

 partly to fluctuations in temperature. The extreme de- 

 flection of the new Black well's Island bridge is expected 

 to be about 20 inches. This latter bridge is unique among 

 long-span bridges in respect of the cantilever arms meet- 

 ing in the centre without any intervening span. 



Messrs. Const.able and Co., Ltd., have just published 

 a cheap edition (2s. 6d. net) of Prof. H. H. Turner's 

 " Modern Astronomy," originally issued in 1901, and re- 

 viewed in Nature of March 21 of that year (vol. Ixiii., 

 p. 488). The book gives an admirable account of instru- 

 ments, methods, and results of astronomy during the last 

 quarter of the nineteenth century, and should now reach 

 a wide circle of readers. 



The fifteenth volume of the new series of the " Reliquary 

 and Illustrated Archaeologist " has been published by 

 Messrs. George Allen and Sons at the price of 12s. net. 

 The volume contains the four quarterly parts issued this 

 year, the contents of which have been referred to in these 

 columns as the parts first appeared. It forms a handsome, 

 well-illustrated book, which should appeal to all readers 

 interested in early Pagan and Christian antiquities, 

 mediaeval architecture, the survivals of ancient usages, and 

 similar subjects. 



Messrs. Witherby and Co. have published a second 

 edition of Mr. M. J. Nicoll's " Three Voyages of a 

 Naturalist," being an account of many little known islands 

 in three oceans visited by the Valhalla, R.Y.S. The 

 original issue of the book was reviewed in Nature for 

 May 14, 1908 (vol. Ixxviii., p. 32), when one of its 

 numerous illustrations was reproduced. The only material 

 alteration in the second edition is in chapter xx., where 

 the statement has been corrected that Easter Island, when 

 first discovered, was uninhabited. 



A SECOND edition of " A Treatise on Concrete, Plain and 

 Reinforced," by Dr. F. VV. Taylor and Mr. S. E. Thomp- 

 son, with chapters by various other writers, has been pub- 

 lished by Messrs. John Wiley and Sons in New York, and 

 by Messrs. Chapman and Hall, Ltd., in this country. The 

 first edition was reviewed in our issue of March 15, 1906 

 (vol. Ixxiii., p. 457). The second edition aims to cover the 

 developments in the design and construction of reinforced 

 concrete since 1905, and to this end more than two hundred 

 pages of new matter have been added. The price of the 

 new edition is five dollars. 



Messrs. Baird and Tatlock (London), Ltd., have sent 

 us a copy of their latest catalogue of general apparatus. 

 The comprehensive character of the catalogue will be 

 gathered from the fact that it runs to 848 large pages. 

 Sections are included in the list dealing with different types 

 of laboratory and other benches, fume cupboards, and 

 other fittings ; the special apparatus required for physico- 

 chemical experiments, and instruments necessary for milk, 



