============================================= Temperature |Correction to be added |with flasks having a | volume of— ----------+----------+------------+---------- Fahrenheit|Centigrade| 125 cc. | 400 cc. ----------+----------+------------+---------- | | _Grams_ | _Grams_ 69 | 20.6 | .02 | .05 70 | 21.1 | .03 | .09 71 | 21.7 | .05 | .14 72 | 22.2 | .06 | .20 73 | 22.8 | .08 | .25 | | | 74 | 23.3 | .09 | .30 75 | 23.9 | .11 | .35 76 | 24.4 | .13 | .41 77 | 25.0 | .15 | .47 78 | 25.6 | .17 | .53 | | | 79 | 26.1 | .18 | .59 80 | 26.7 | .20 | .65 81 | 27.2 | .22 | .71 82 | 27.8 | .24 | .77 | | | 83 | 28.3 | .26 | .83 84 | 28.9 | .28 | .89 85 | 29.4 | .30 | .96 86 | 30.0 | .32 | 1.02 ----------+----------+------------+---------- If it is desired to use somewhat larger samples and thus secure correspondingly more accurate results, a similar flask, but made somewhat larger (capacity approximately 400 cc.), may be employed. Such a flask, with a diameter of a little over 3 inches, is illustrated in Figure 2. This larger flask will not fit into the Babcock tester, and when it is used a special head for the Babcock tester must be made. Such a head is illustrated in Figure 3, and can be made by any good tinner. The larger flask shown in Figure 2 holds a heavier weight than the Babcock machine is intended to carry, and the advisability of its use is perhaps questionable. In any case, whatever size flask is used, it is important to build a guard around the centrifuge in order to protect the operator when the apparatus gives way, as it eventually will. [Illustration: Fig. 1. Small Specific Gravity Flask. Fig. 2. Large Specific Gravity Flask. Dimensions given are outside measurements. Thickness of walls is about 3/64 in.] The details of the method of determining specific gravity by the use of this apparatus are as follows: