5 2 



SCIENCE- GOSSIP. 



occasions may arise. The Council announce that 

 the members of L'Union Internationale de 

 Photographie have decided to hold their annual 

 gathering at Oxford in conjunction with the Photo- 

 graphic Convention of the United Kingdom. There 

 is this year every prospect of a very enjoyable and 

 successful meeting, and the Hon. Secretary is to be 

 congratulated upon the complete arrangements he 

 has provided for the members. 



Colour Photography. — We have received a 

 fully illustrated and descriptive catalogue of appa- 

 ratus, material, and appliances for natural colour 

 photography, a simple, inexpensive, and reliable 

 process, based upon sound scientific principles for 

 obtaining photographs of any object in natural 

 colours. Many attempts have been made to intro- 

 duce methods of obtaining natural colour photo- 

 graphs with more or less success from the time 

 when Professor Clerk-Maxwell first projected a 

 photograph in natural colours upon the lantern 

 screen at the Koyal Institution in 1861. The 

 method by which he obtained his results was based 

 upon the Young-Helmholtz theory of colour vision, 

 which assumes that there are three fundamental 

 colour sensations — viz. a red, a green, and a violet. 

 Upon these lines Mr. Frederick Ives, of Phila- 

 delphia, succeeded in producing, by his Kromskop 

 system, colour photography. It was a colour 

 record or transparency, which, when viewed in a 

 special instrument, had an effect faithful in colour 

 to the original and pleasing to the eye. Since, 

 however, Mr. Ives left this country, where he per- 

 fected his system of colour photographs, the work 

 has been carried on by Messrs. Sanger Shepherd 

 & Co., who have brought the process to a degree of 

 perfection, and so simplified the working details, 

 as to place it within the reach of every careful 

 worker in photography. The enormous 

 number of subjects to which this pro- 

 cess of pure colour photography is 

 specially applicable is obvious. Every 

 piece of special apparatus that is re- 

 quired for this process is carefully illus- 

 trated and explained in the list, and 

 we should recommend anyone interested 

 in this beautiful method of reproducing 

 nature to write to Messrs. Sanger 

 Shepherd & Co., Cray's Inn Passage, 

 Red Lion Street, London, who, we are 

 sure, would be pleased to forward the 

 catalogue and supply any information that would 

 be required. 



PHOTOGRAPHY FOR BEGINNERS. 

 By B. Foulkes-Winks, M.R.P.S. 



(Continued from page 23.) 



Section I. Cameras (continued). 



In addition to the "Yale" hand-cameras, Messrs. 

 Adams & Co. are manufacturers of the " Adams 

 De Luxe " double-extending camera, the " Reflex " 

 and the " Natti " cameras. We give illustrations 

 of the " Adams De Luxe." It is an instrument of 

 the very highest type, and beautifully finished in 

 every detail. It is fitted with the " Ross-Zeiss " 

 convertible Anastigmat lens, working at F. 6'3 in 

 its combined form, and at F. 12-5 when used as a 

 single lens. In the J-plate size the lens fitted is 

 the No. i, and when used as a double lens is of 

 5-inch focus if used as a single lens, the focal 



length is 9 inches. The front combination of the 

 lens is easily removed by a simple bayonet joint, 

 and slipped into a spring clip provided for the 

 purpose of holding the front lens when not in use. 

 The camera is then racked out to its full extent by 

 a very ingenious double rack-work arrangement, 

 by which means the front and back portions of the 

 camera move equally away from the centre, carry- 

 ing the handle, thus keeping the weight always 



Fig. 1. Adams' "De Luxe," closed. 



central. There are two separate distance scales 

 supplied, one for each lens ; the diaphragm values 

 are engraved for each lens ; and the finders, which 

 are of the " Brilliant Real Image " type, are pro- 

 vided with shields, so that they will show the 

 exact amount of view embraced by either lens. 

 A most important point about these finders is that 

 they move in exact relation to the rising front of 

 the camera ; the operator will therefore be able to 

 judge the precise amount of foreground it is desir- 

 able to cut off from the picture he is taking. This 

 applies both to the horizontal and vertical finder. 

 They are also perfectly adjusted, and show in 

 miniature the exact view that will be upon the 

 plate. The camera is fitted with the patent pneu- 



ms' "De Luxe," extended for r/si 



Lexs- 



matic regulation shutter, working between the 

 lenses, and giving a range of' speeds from h a second 

 to j^ 5 th of a second. It is also fitted with a focal 

 plane shutter, giving a further range of speeds 

 varying from jJoth to josoth of a second. Thus, 

 with this camera any exposure may be given 

 between J a second and xSoott 1 for .time ex- 

 posure. The pneumatic or front shutter is 

 used, and for this purpose an india-i'ubber ball 

 tube release is provided. The changing-box, 

 which carries either twelve plates or twenty-four 

 cut films, is built upon the " Yale " system, as 

 described in last mouth's issue of Science-Gossip 

 (p. 23). The box is provided with an automatic 

 indicator, which records the number of plates 

 exposed. The changing-box can be easily removed 

 from the camera and a ground glass focussing 

 screen inserted in its stead for use when the camera 

 is on a tripod. It is so constructed that double 

 dark slides may be used in the camera, which are 

 made interchangeable with the changing-box. 

 The Camera De Luxe is provided with an extensive 



