PRICE OF INSTRUMENTS AND APPARATUS 137 



1/12-in. Achromatic object glass (2 ram.), Oil- 

 immersion ..... 

 li-in. Apochromatic object glass (40 mm.) 

 2/3-in. Apochromatic object glass (16 mm.) 

 2/3-in. Apochromatic object glass (14 mm.) 

 1/3-in. Apochromatic object glass (8 mm.) 

 1/6-in. Apochromatic object glass (4 mm.'i 

 1/6-in. Apochromatic object glass (4 mm.), with 



correction collar .... 



1/12-in. Apochromatic object glass (2 mm.), Oil 



imm.ersion ..... 



42-mm. x 6 Huyghenian eyepiece . 

 25-mm. x 10 Huyghenian eyepiece 

 17-mm. X 15 Huyghenian eyepiece 

 45-mm. X 6 Compensating eyepiece 

 30-mm. X 8 Compensating eyejjiece 

 22-mm. X 11 Compensating eyepiece 

 15-mm. X 17 Compensating eyepiece 

 10-mm. X 25 Compensating eyepiece 

 Beck micrometer eyepiece 

 Eyepiece with indicator 

 Eyepiece with cross- wires 

 Erecting eyepiece .... 



£ s. 



LARGE SIZE EYEPIECES 1-41 INCH DIAMETER OF TUBE 



Eyeshade ..... 

 42-mm. X 6 Huyghenian eyepiece . 

 25-mm. X 10 Huyghenian eyepiece 

 17-mm. X 15 Huyghenian eyepiece 



APPARATUS FOR ILLUMINATING OBJECTS 



3285 26 



3285p 33 



3286 26 



3286p 33 

 3287 27 



3288 27 



3288p 33 

 3291 28 



3284 33 

 3295 34 



3296 34 



Small Abbe condenser, fitting with iris dia- 

 phragm on Microscopes No. 3210 and 3211 . 



Set of patch-stops for above .... 



Large Abbe condenser in fitting with iris dia- 

 phragm and swing-out tray for colour screens 

 with coloured and ground glass . 



Set of three patch-stops for above . 



Beck dry achromatic condenser, 1 N.A., lenses 

 only in mount, with standard object glass, 

 screw thread ....•• 



Beck dry achromatic condenser, 1 N.A., com- 

 plete in fitting with iris diaphragm and swing- 

 out tray, grey and green glass . 



Set of three patch-stops for No. 3288 or 3290 . 



Beck dry and immersion achromatic and apla- 

 natic condenser, 1-3 N.A., in mount, with iris 

 diaphragm and tray for patch-stops and \yith 

 ground and green glass double-wedge light 

 moderator ...••• 



Traviss expanding iris patch-stop . . . 



High-power dark-gromid illuminator, optical 

 portion only in mount, with standard object 

 glass thread . . • • • • 



Illuminator as above in plain substage fitting . 



4 5 



5 15 

 7 6 



