Fs Le 
SCIENCE 
NEW SERIES. SINGLE Copizs, 15 crs. 
Vou. VI. No. 137. FRIDAY, AUGUST 13, 1897. ANNUAL SUBSCRIPTION, $5.00. 
T™me QUEEN PHAROS 
AUTOMATIC ELECTRIC LAMP. 
ITS TWELVE POINTS OF SUPERIORITY: 
1. It Keeps in Focus Constantly 8. Does NOT FLICKER nor 
2. Regulates and Runs Silently | ESA 0 ‘ 
. Its Light Power is the High- é 
3. Regulates at Short Intervals 
G55. 4, on) 6! 6 boo ¢ 6 
. The FULL CRATER is Pro- 
jected . 
4. The Carbons Separate Very 
Little 
5. ItLights up the Screen Evenly , Whe Neate Cacbyn tation 
6. Maintains the Same Intensity Luminous . 
7. No Attention Required TO 
HELP it Regulate 
. The Adjustments are all 
Outside 
SPECIALLY DESIGNED FOR PROJECTION IN THE PHYSICAL LABORATORY AND LECTURE ROOM. 
TS mechanism is contained in a nickel-plated case about four and a half inches high, five 
inches long, two and a quarter inches wide. The carbon holders and gears are placed 
outside on the narrow front, but the carbons are enclosed in a box with a circular window 
holding a glass screen to protect the lenses from sparks given off by the arc light. 
QUEEN PROJECTION MICROSCOPE. THE MICRO-POLARISCOPE. 
STAUROSCOPE with latest improvements, stand unexcelled. 
... PROJECTION APPARATUS OF ALL KINDS.... 
Microscopes, Engineering Instruments, Physical and Chemical 
Apparatus, Electrical Test Instruments. 
Catalogues and Circulars 
on application to QUEEN & Co., INC., 
New York Office: 116 Fulton St. 1010 Chestnut St., Philadelphia. 
