PeNvE Lh KLY ILEUS TRAD 
“To the 
the 
soli 
O, Nature trusts 
mind which burlds 
D JOURNAL OF SCIENCE. 
7 ground 
Sor aye.”—WORDSWORTH. 
No. 1429, VOL. 55] THURSDAY, M 
ARCH 18, 1897. [PRICE SIXPENCE. 
Registered as a Newspaper at the General Post Office.) 
[All Rights are Reserved. 
LANTERN SLIDES 
NANSEN'S P POLAR EXPEDITION 
NEWTON & CO., ov 3 FLEET STREET, E.C., 
Have obtained the sole Ae to manufacture and sell Lantern 
Slides of Dr. NANSEN’s Pictures in 
«“PRPARTHEST NORTH.” 
Price 2S, each. List post free. 
The Slides are printed from the same Negatives as those 
used by Dr. Nansen at his own Lectures, which were made | 
for him by Newron & Co. 
As the demand for these will probably be large, early | 
application is advisable. 
‘A series of singularly beautiful photographic illustra- 
tions.” — Zhe Times, ey g, 1897. 
X-RAY COMPLETE SETS. 
Ser A. Including 3-inch Coil, our own make, Batteries, Focus 
Tube, Jule Holder, Barium-Platino-Cyanide Screen, 
7in. X si ; £13 0 0 
SET *B. lacie 6-inch Coil, Batteries, r r Foc us is Tube, 
Tube Holder, Barium- Platino- Cyanide Screen, 9fin. x 7in. £23 10 0 
BARIUM-PLATINO-CYANIDE SCREENS. 
EXCELLENT FLUORESCENCE, in neat Frames with Handles. 
7 in. X 5 in., 218.3 gh in. x 7 in., 325. 6¢. ; 11} in. X of in., 555. 
JOHN J: GRIFFIN & SONS, LC 
22 GARRICK STREET, LONDON, W.C. 
NALDER BROS. & CO. 
| 16 RED LION STREET, LONDON, E.C. 
| — 
| 
| 
| 
my ay TPT TITY 
8 7 
[Exrows beeen 
|THE NG. 8. PATTERN OF THE TROTTER BAR PHOTOMETER 
This was the Instrument selected by the General Post Office for their 
tests on Incandescent Lamps. (See Electrician, October 2, 1896, p. 738-) 
Much easier to read than either the shadow or grease-spot instrument. 
Complete with Scale mounted on Bar, and 100 Volt Standardised Lamp. 
Price ‘59. 
WRITE FoR Cat ALOGUE. Cable Address, “SEcoum, Lonpon. 
No Agents, U.S.A. This Instrument delivered anywhere in U.S.A., but 
with unmounted scale, for $54. 
NEGRETTI AND ZAMBRA’S 
BAROGRAPHS AND THERMOGRAPHS. 
: 
The Barone is fitted i in a eteeee Ges with Glass Front, as shown 
above. The Thermograph is mounted in a japanned Metal Case with Glass 
Front, for either indoor or outdoor use. The above give continuous records 
on Charts, which only require changing once a week, and are invaluable to 
valids and others who are unable to’ take daily readings of the ordinary 
asia Price of each, with supply of Charts for one year, £6 10s. 
NEGRETTI & ZAMBRA, 
ScIENTIFIC INSTRUMENT MAKERS TO THE QUEEN, 
38 HOLBORN VIADUCT, E.C. 
Branches—45 CORNHILL, and 122 REGENT STREET. 
