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Measuring Scales and fully divided Circles. 



We are prepared to supply measuring scales on nickel -silver or 



plate-glass in any form desired. The following are a few patterns regularly 

 stocked by us: 



Nickel-silver Rule: 



No. 131: 1O cm divided in millimetres. 



Price: Marks 3.50. Code-word: Pecunia. 



Rules on plate-glass: 



132: 5 cm divided in l /% millimetres. 



Price: Marks 2.50. Code-word: Pedaceria. 

 133: 10 cm divided in millimetres. 



Price: Marks 3.50. Code-word: Pedagogo. 



134: 20 cm divided in millimetres. 



Price: Marks 7. . Code-word: Pedano. 



135: 30 cm divided in millimetres. 



Price: Marks 12. . Code-word: Pedestal. 



Rules on plate-glass with double scale, one side in millimetres, the other 

 in English inches. 



No. 136: 5 cm divided in l / 2 millimetres (2 inches in 48 parts). 

 Price: Marks 3.50. Code-word: Pedido. 



137: 10 cm divided in millimetres (4 inches divided in 48 parts). 

 Price: Marks 4.50. Code-word: Pediluvio. 



Fully divided Circles on plate-glass are kept in stock in the two 



following sizes: 



No. 138: Circles of 80 mm (3 l / s in.) diameter divided in l /^ degrees. 



Price: Marks w. . Code-word: Pedometro. 



139: Circles of 12O mm (4 3 /4 in.) diameter, divided in l / 2 degrees. 

 Price: Marks 75. . Code- word: Pedrada. 



The nickel-silver rules have bevelled edges. In rules on plate-glass and in the 

 fully divided circles the figures are in mirror-type so that the divisions may be laid 

 on the surface of objects to be measured and be easily read off without parallax. 



Appliances for Counting, 



Cross-line Micrometers are usually employed for counting small objects, 

 such as blood-corpuscles, yeast-cells, bacteria, &c. 



We supply an Eye-piece cross-line Micrometer to rest on the diaphragm 

 of the eye-piece or, preferably, for use with a micrometer eye-piece having an 



