348 



SCIENCE-G OS SIP. 



COXDTTCTED BT B. FOFLKES-WIXKS. M.R.P.S. 



EXPOSUEE TABLE FOR MARCH. 



The figures in the following table are worked out for plates of 

 about 100 Hurter & Driffield. For plates of lower speed number 

 eive more exposure in proportion. Thus plates of 50 H. <fc D. 

 would require just double the exposure. In the same way, 

 plates of a higher speed number will require proportionatelv 

 less exposure. 



Time, 10 A.M. to 2 p.m. 



Between 9 and 10 a.m. and 2 and 3 p.m. double 



the required exposure. Between 8 and 9 a.m. and 



3 and 4 p.m. multiply by 4. 



Subject F.5-6 F. 8 F.ll F. 16 F. 22 F.32 F.45 F.64 



; Sea and Sky.. 



Open Landscape 

 and Shipping | 



Landscape, w'th \ 

 dark fore- [ 

 ground, Street - :! V 

 Scenes, and i I 

 Groups . . ) 



Portraits in >_ „ 

 Booms . . J 



Light Interiors i 4 



Dark Interiors 1 6 



A 1 x 



i 1 



4 8 16 32 



32 



8 16 30 



The small figures represent seconds, large figures; minutes. 

 The exposures are calculated for sunshine. If the weather is 

 cloudy, increase the exposure by half as much again ; if gloomy, 

 double the exposure. 



Royal Photographic Society. — At the annual 

 general meeting held on Tuesday. February 12th. 

 1901. in the Society's Rooms at 66 Russell Square. 

 W.C.. Mr. Thomas R, Dallmeyer. F.R.A.S.. the 

 President, in the chair, the Society's " Silver 

 Progress Medal ' was formally presented to Dr. 

 R. L. Maddox. Mr. Bedding. Editor of the - British 

 Journal of Photography.'' received the medal on 

 behalf of Dr. Maddox. who was unfortunately 

 unable to be present, owing, we are sorry to say. 

 to age and infirmities preventing him travelling to 

 London. The President expressed the pleasure it 

 gave him at being privileged to make this presenta- 

 tion. Dr. Maddox has devoted much time and 

 stud}- to Photomicrography, of which he was a very 

 brillant exponent ; but the reason the Society had 

 awarded him this Progress Medal was for the 

 introduction of the gelatino-bromide of silver dry 

 plate. Of photography it might truly be said that 

 the introduction of the gelatino-bromide dry plate 

 had done more for the art than had any single step 

 of progress since the days of Daguerre. Of the 

 many thousands who practise the art to-day. from 

 the operator in the studio to the amateur who is 

 satisfied with a little " snapshotting " on his oi- 

 lier holiday tour, all are more or less indebted to 

 Dr. Maddox. The "Journal " of the Society is just 

 to hand, and we see that as yet there are only 

 two meetings down for April : they are April 2nd. 



Lantern meeting, when Mr. Charles Reid will give 

 an illustrated lecture entitled •' Animals and Birds 

 in their Native Haunt " ; and April 9th, an ordinary 

 meeting. when Mr. Wm. Webster will read a paper 

 entitled " Notes from Five Years' iWork with X- 

 Rays." 



Telephoto-Lexses. — Messrs. Staley k. Co. have 

 submitted to us for inspection and trial a new tele- 

 attachment, made by Bausch & Lomb, of Rochester. 

 L'.S.A. The leading feature of the attachment is 

 that it can be fitted to any existing lens of a given 

 focus. They are made in various sizes and nega- 

 tive power, so that all that is necessary is to sen<! 

 through a dealer the focal length of any lens that 

 it is desired to convert into a telephoto-lens. and 

 a suitable attachment can be supplied. These are 

 so made that they may very readily be attached to 

 a lens, and as easily detached when not in use. 

 They are of moderate magnifying power, enlarging 

 from two to four and a half times, and can be used 

 on any ordinary camera with moderate amount of 

 extension. These attachments are very low in 

 price, varying from 40s. upwards, according to the 

 focal length of lens to which they are to be at- 

 tached. We understand that these lenses can also 

 be supplied as a complete telephoto-lens and 

 shutter : that is to say. a rapid symmetrical 

 lens, with Bausch ic Lomb shutter and negative 

 attachment, price complete for |-plate being 75s. 

 At the usual distance the lenses commonly em- 

 ployed for photography are all that is necessary 

 for satisfactory results. When, however, it is 

 impossible to approach close enough to the object 

 to secure an image of the desired size with the 

 ordinary lens the telephoto-lens is the only re- 

 source. The amateur of experience knows how 

 often this happens. 



Novelties. — Mr. Arthur Payment, of Fore.-t 

 Gate. E., has introduced several novelties in con- 

 nection with folding film cameras. The " Adapter 

 G-uenault " is a small metal dark slide that enables 

 the possessor of a film camera to use ordinary glass 

 dry plates or cut films. It is easily adapted, and 

 requires no alteration to the camera, the dark slide 

 being held in position merely by friction. We are 

 convinced that this simple little arrangement will 

 prove a real boon to users of folding Kodak.-, 

 who will now be enabled to make one or two 

 exposures, and to develop them at once, with- 

 out having to wait until a whole spool of 

 film is exposed before development is pos- 

 sible. Mr. Rayment is also adapting to folding - 

 Kodaks the " Steinheil Anastigmat" lens working 

 at F. 6'3, and fitted to Steinheil's time and instan- 

 taneous shutter. Thus the value of a folding 

 Kodak can be greatly increased and its efnciency 

 modernised. We must not overlook that useful 

 little novelty of Guenault's. a pneumatic shutter 

 release, which can be rapidly applied to any fold- 

 ing Kodak, and acts in conjunction with the 

 shutter supplied with the camera. This will be 

 found especially valuable to amateurs who have a 

 difficulty in holding the camera steady during 

 exposure. It will be useful also for time exposure, 

 for it obviates the necessity of touching the 

 camera. Whilst on the subject of folding Kodak 

 cameras we would remind our readers that the 

 Kodrtk Company are now supplying spools with 

 four exposures in two separate pieces, permitting 

 two exposures to be made. These two can be 

 removed from the camera, and another two-ex- 

 posure film remains in the camera for future use. 



