Latent heat of fusion of ice . o be — o?72 C. With the magnesium sulphatemixture the observations showed that the temperature of thespecimen should be taken as — 3^78 C. 4. HANDLING THE SPECIMENS For handling the specimens, when packing them in the cryo-stats, weighing, and transferring to the calorimeter, they wereinclosed in holders made of sheet copper, as shown in Fig. 6. Thebar across the top which carries the supporting ring is detachablefor inserting the specimen. Each was provided with a loop oflinen thread passed through the ring, by means of which thespecimen could be transferred to
Latent heat of fusion of ice . o be — o?72 C. With the magnesium sulphatemixture the observations showed that the temperature of thespecimen should be taken as — 3^78 C. 4. HANDLING THE SPECIMENS For handling the specimens, when packing them in the cryo-stats, weighing, and transferring to the calorimeter, they wereinclosed in holders made of sheet copper, as shown in Fig. 6. Thebar across the top which carries the supporting ring is detachablefor inserting the specimen. Each was provided with a loop oflinen thread passed through the ring, by means of which thespecimen could be transferred to the weighing cryostat and thenlifted until the suspension hook was engaged in the ring. Thethread was then cut and removed, leaving the specimen hanging,as shown in Fig. 7. After weighing, the specimen was trans-ferred to the calorimeter by lifting the cover vessel, suspensionhook, and specimen together from the cryostat, carefully lower- Dickinson, Harper,!Osborne J Latent Heat of Fusion of Ice 249 %^3x fill »<1 H 1°. 6-5:6^5pep $ til ?„& §§£% ^M^Sfc^ Fig. 7.—Section through oyostat, by use of which ice specimens were brought to a fixed,known temperature 250 Bulletin of the Bureau of Standards [ ing the specimen into the open calorimeter, and then detachingthe hook, leaving the specimen immersed in the water. Thistransfer required only two to three seconds. 5. WEIGHING THE SPECIMENS The precooled specimens were weighed while suspended in thecryostat (Fig. 7) placed beneath the balance. A suspension wirefrom a hook under the left balance pan led down through the bal-ance support to the hook extending into the cryostat. Themethod of substitution was used in weighing. A fixed counter-poise was kept upon the right pan throughout the the specimen suspended the weights necessary upon theleft pan were determined. After the specimen was removed forthe determination, the suspension alone was balanced, the dif-ference between this and the previous
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Keywords: ., bookcentury1900, bookdecade1910, bookidlat102352661914209209unse
