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SCIENCE- G OSS/P. 



est class instruments in the market and the most 

 complete in every respect. The principal makes 

 and some of the best instruments are : Adams & 

 Co.'s " Yale" and " De Luxe," Newman & Guardia's 

 " N & G " camera, Watson's " Vanneck," and the 

 " Eouch." The two firms first mentioned make de- 

 tachable changing boxes, which are supplied with 

 several other makers' cameras, such as the " Gam- 

 bier-Bolton," etc. This system of changing is used 

 largely for cut films, in which case the cut film is 

 inserted in the _ sheath, in the same way that the 

 plate is carried. 



Cut Films There are very few cameras made 



only for cut films, the most important of these 

 being the "Frena" and the "Telia." The chang- 

 ing system is somewhat similar in each case : that 

 is to say, films are put into packets of twenty or 

 twenty-five, as the case may be ; each camera hold- 

 ing as many as forty or fifty films. When the first 

 film is exposed it is passed away into the receiving 

 chamber, and the next film comes into position 

 ready to receive an impression. The mechanism 

 in each case is exceedingly ingenious, and achieves 

 a very difficult operation in separating one film 

 from another. 



Rolled Films. — Films capable of being rolled 

 are used almost exclusively in the Eastman 

 " kodak." They consist of a very thin film of 

 celluloid coated with a sensitive emulsion. This 

 is wound, in conjunction with a strip of black paper, 

 upon a spool which fits into the camera. It is 

 then passed across the focal plane of the lens on 

 to another and empty spool, and is gradually 

 wound off one spool to the other. Thus we get a 

 series of pictures upon a long strip of sensitive 

 film, which, when developed, may be cut up into 

 its several parts, as may be desired. The great 

 charm of this changing system is the fact that a 

 spool can be inserted into the camera in broad 

 daylight, six or twelve exposures made, and the 

 film wound off, taken out of the camera, and a 

 new spool inserted. It occupies little space, and 

 is very light in weight. 



Having decided upon the changing system, there 

 are other essential points to consider in a hand 

 camera. 



Lenses. — A good quick-acting lens is necessary, 

 one with iris diaphragms working from F. 8 to 

 F. 32 if desirable, and in the best instruments with 

 lenses of the anastigmat type from F. 6-3. 



Shutters. — A time and instantaneous shutter 

 is required, giving exposures varying from ^ to 

 T i 5 part of a second ; also for indefinitetime. With 

 cameras fitted with the quickest lenses, such as the 

 " Planar," a range of speed from J to ^g part of 

 a second is desirable. The shutter should not open 

 when being set. We think the most satisfactory 

 method of timing a shutter is beyond question the 

 pneumatic regulation principle, as used by New- 

 man & Guardia, Adams & Co., and Bausch & 

 Lomb. 



Rising Fronts.— In addition to the above points, 

 we strongly advise the student to select a hand 

 camera having a rising front. (See Stand Cameras, 

 ante, p. 253.) 



Focussing. — A rack -work focussing arrangement 

 is most important. 



(To be continued.") 



John Henry Leech. — What at one time appeared 

 to promise a brilliant scientific career was closed, we 

 understand by the breaking of a blood-vessel, on 

 December 29th last. Mr. Leech, born thirty-eight 

 years ago, w r as educated at Eton and Trinity Hall, 

 Cambridge. He was the son of the late John 

 Leech, Gorse Hall, DukinfLeld, Cheshire, and on 

 attaining his majority he inherited very ample 

 means. J. H. Leech was a born naturalist and no 

 mere collector. At an early age he cut himself 

 adrift from the narrowing influences of a mere 

 British collector, following the pursuit of ento- 

 mology and sport as a traveller in little-known 

 districts of Central Brazil, Northern India, Corea, 

 and Japan. During this period Mr. Leech passed 

 through many dangerous adventures and serious 

 risk from climatic diseases ; in fact, it is probable 

 that the seeds were sown which ultimately so 

 sadly cut short a life useful to science. After 

 these extensive wanderings Mr. Leech commenced 

 to scientifically investigate his large collection of 

 lepidoptera, and soon became a specialist in those 

 species constituting the fauna of Eastern Asia. To 

 the collections already in his hands he largely 

 added by employing both European and native 

 collectors in China, Japan, Corea, and portions of 

 the Palaearctic region, thus amassing material to 

 an extent rarely exceeded by any private collector. 

 The result has been the publication of an important 

 illustrated work on the butterflies of China, Japan, 

 and Corea, and the formation of a magnificent type 

 collection of Eastern lepidoptera. For sometime past 

 the butterflies in this collection have been offered for 

 sale, but as the price was several thousand pounds 

 we hear that they have not yet found a purchaser. 

 A large supernumerary collection of Heterocera 

 from the same region, in addition to Mr. Leech's 

 own types and series, was some time ago acquired 

 for the national collection at South Kensington. 

 Mr. Leech was a B.A. of Cambridge, a F.L.S., 

 F.Z.S., F.E.S., and author of a small work on 

 British Pyralides, published in 1885. He was an 

 ardent sportsman, which led to the unfortunate 

 loss of his left forearm by the bursting of a 

 sporting gun while pheasant shooting in Cam- 

 bridgeshire, and the bearing with extraordinary 

 fortitude of two amputations with a considerable 

 interval between. With his usual resolution, he 

 habituated himself to his loss, and became, with 

 one hand only, as expert as most men with both 

 hands. He was also an exceptionally clever 

 fisherman, and contributed piscatorial articles to 

 the " Badminton Magazine," " Baily's Magazine," 

 and elsewhere. For some years Mr. Leech was 

 the proprietor of the "Entomologist," which was 

 edited by his scientific assistant, Mr. Richard 

 South. The funeral of Mr. Leech took place at 

 Baverstock, near Hurdcott House, Salisbury, where 

 he died. We have not heard the destination of 

 the collections ; it is improbable his widow will 

 encounter the responsibility of their care and pos- 

 sible rapid deterioration. 



