CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 



53 



630. BALANCE, Spring, English, cylindrical pocket form, arranged 

 to obviate the zero error. Reads to 15 Ibs. in 4 oz. divisions. 

 Spring elongates 2^4 inches $0.70 



632. BALANCE, Spring, English, 25 pounds in 8 ounce 

 divisions. Spring elongates 1^ inches. . .20 



634. BALANCE, Spring, English. 50 Ibs. in 1 Ib. di- 

 visions. Spring elongates 1% inches. . . . .36 



636. BALANCE, Spring, English 

 and Metric, with flat b.ick 

 and broad pointer, for either 

 perpendicular or horizontal 

 reading. Reads to 8 oz. in % 

 oz. divisions, and 250 grams 

 in 10 gram divisions. Spring 

 elongates 2>4 inches. . 1.10 



638. BALANCE, Spring, English 

 and Metric, with flat back 

 and broad pointer, for either 

 perpendicular or horizontal 

 reading. Reads to 64 oz. in 

 1 oz. divisions, and 2,000 



rams in 25 gram divisions, 

 priug elongates 2*4 inches. 

 60 



640. BALANCE, Spring, English 

 and Metric. Capacity, IS oz. 

 in 1/5 oz. divisions and 500 

 grams in 10 gram divisions. 

 Has flat back and sharp 

 pointer, and is provided with 

 several divisions above the 

 zero to compensate for the 

 sharp pointer in horizontal 



readings. Spring elongates No. 630. No. 636. No. 638. 

 to 4 inches.. 3.30 



No. 640. 



No. 644. 



642. BALANCE, Spring, English and Metric, with flat back. Beads to 30 Ibs. in % Ib. divisions, and 

 15 kilos in 100 gram divisions. Spring elongates 5^ inches 2.30 



644. BALANCE, Spring, English and Metric, in iron case with sliding index recorder. Especially 

 designed for experiments in tensile strength, the indicator remaining at the breaking strain, 

 instead of going back to zero when the strain is released, as in the ease of the regular spring 

 balances. Reads to 30 Ibs. in *4 Ib. divisions, and 15 kilos in 100 gram divisions. Spring 

 elongates 5^ inches 8.00 



646. BALANCE, Stoddard Labora- 

 tory, designed by Prof. J. T. 

 Stoddard, Department of 

 Chemistry, Smith College, 

 Northampton, Mass. Capacity 

 121 grams; sensibility, less 

 than 1 eg. Especially suited 

 for use in Elementary Chem- 

 istry, sine* it is much more 

 accurate and easy to handle 

 than tfce Horn Pan Balance, 

 and more durable than the 

 cheap equal arm Chemical 

 Balance. 



Five riders are furnished, 

 which weigh 10 g., 1 g., 1 g., 

 0.1 g., and 0.01 g., respective- 

 ly, when placed on the first 



notch on the beam. These values multiplied by the number of the notch give the weight re- 

 quired. For example, the balance in the illustration is in equilibrium with a mass of 37.7 grams 

 in the pan. When not in use the riders are kept in a covered receptacle permanently attached 

 to the base of the balance 7-50 



No. 646. 



