79 



Appliances for measuring thicknesses. 



Xo. 12',). Dial Cover-glass Gauge. The apparatus serves the purpose 

 of estimating the exact measurement of the thickness of cover-glasses, thin 

 plates, etc. - The measurement is effected by means of a clip projecting from 

 a box-shaped round casing. The reading is given by an indicator moving over 

 n divided circle on the lid of the box. The divisions show hundredths of a 

 millimetre. The gauge measures thicknesses up to 8 mm. 



Xo. 130. Cover-glass Gauge of simpler construction. This instrument 

 consists mainly of a screw with divided drum and, like the preceding, records 

 readings of 0.01 mm. 



Measuring Scales and fully divided Circles. 



Xos. 131 to 139. 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: 



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. 



138 

 13!) 



Dial Cover-glass Gauge 



Cover-glass Gauge, simpler construction 



Nickel-silver Rule, 10 cm divided in millimetres . . . . 



Rules on Plate-glass with simple ruling: 



5 cm divided in l j t millimetres 



10 millimetres 



20 



30 

 Rules on Plate-glass, double scale (one side in millimetres, 



the other in inches): 



5 cm in half millimetres (2 ins. in 48 parts) . . . . 

 10 cm in whole millimetres (4 ins. in 48 parts) . . . 



Fully divided Circles on Plate-glass: 



Circle of 80 mm diameter divided in degrees . . . 

 120 half degrees. . 



Marks Codeword 



30 Pecora 



15. Pectoral 



4. Pecunia 



3. 

 ^ 



8. 

 12. 



4.50 

 6.- 



14. 

 20. 



Pedaceria 

 Pedagogo 

 Pedano 

 Pedestal 



Pedldo 

 Pediluvio 



Pedometro 

 Pedrada 



