clviii 



NA TURE 



r^*iUGusT 17, 1905 



^ THE CAIFFE AUTO-MOTOR 

 IVIERCURY JET INTERRUPTER 



(Patented in Britain). 



NO BRUSHES, NO BANDS, NO INDEPENDENT MOTOR. 



The intetrupdon cuts the current bnih for motor and coil. 

 In other words, motor and interrupter are electrically and 

 mechanically linked together. 



E*^ See Nature, July 20, ,005, fajie z-. 



Price, including box and packing, £4 : 6 : 6 



THE MEDICAL SUPPLY 

 ASSOCIATION, 



22s Gray's Ir>n FSofi-d, L.oncIon, W.C. 



]^£:\?«r nCEIOX^OSOOPIC; SILiXIDiSSS 



the New Is 



of W. WATSON & SONS' No. 3 CATALOGUE, just published. Post Hree 



application. 



Tsetse Flies (G. palplli^), whole insect 



Dissections of all pa'ts may be had mounted separaiely. 



set of I? 



Send for Special Descriptive List. 



Blood-sucking Magkiot (from the Coneo) 



Fly hatched from above, Auchmeyoiityin InteoUi ... 

 Section of Brazilian Quartz, showing cavities contain!; 



Very interesting 

 Eggs of Emperor IVIoth, fertile and sterile, on i slide 



Perfume Glands on Leaf of Lavender 



Hiigula plumosa (Bird's Head coralline). Specially fine mounts 



Karyokinesis in root of Water Lily ... 3 



Leg of Flea, showing muscular structure 



Set of 16 slides illustrating the development of an Ascidian 



(AspersJ) Incase 



Trypanosoma Brucei (Tsetse Fly disease) 



Set of 5 Slides of the Garden Spider, showing different stages of 



SEND FOR THE ABOVE NEWLY PUBLISHED CATALOGUE OF MICRO. OBJECTS. 



tV/irSO/V'S CATALOGUE OF MICROSCOPES {15S pages) is of special interest to all Microscopists, 



post free. 



W. WATSON & SONS, 313 High Hoiborn, London, W.C. 



Branches-16 FORREST ROAD. EDINBURGH, and 2 EASY ROW, BIRMINGHAM. 



OX^^OSSX^JS^ST'S €3i^J%.& ES^O-XRTEZS^ 



RECENTLY 

 REMODELLED. 



Represents K and L 



types, giving- 3 "5 H.P. 



and 5 H.P 



respectively. 



Immediate Delivery 



for Stock Sizes 



of Engines. 



GREAT REDUCTION 

 GAS CONSUMED. 



Up to the end of 1904. 



over 51.000 gas and 

 oil engines had been 



delivered, represent- 

 ing about three- 

 quarters of a million 



actual horse-power. 



THE STIGMATIC LENS. 



SERIES II. F/e. 



Is the best All-round Lens for either Professional or Amateur use. 



Each lens will give perfect definition vi\\\i full aperture \.o the e.\treme corners of the plate 

 it is sold to cover ; with smaller stops it will cover at least two sizes larger, giving perfect sharp- 

 ness all over the plate, and thus becoming a wide-angle lens of the highest e.\cellence. Either 

 combination may be used separately, giving foci of about li and 2 times the length of that of 

 the lens when used intact. The advantage of thus being able to choose the best point of view, 

 irrespective nf distance, will be at once apparent to the artistic worker. 



EQUIVALENT TO FOUR LENSES AT THE PRICE OF ONE. 

 Eleven Sizes are now ready, from 3J to 18 inches eq. focus. 



CATALOGUE OF HIGH-CLASS CAMERAS AND LENSES, POST FREE. 



J. H. DALLMEYER, Ltd., 25 NEWMAN ST., OXFORD ST., LONDON, W. 



MAKERS OF THE CELEBRATED DALLMEYER LENSES. 



