114 C. E. Linebarger — Apjparatus for the Bapid 



elude, then, that the accuracy of a determination of the specific 

 gravity of a liquid, whose surface tension is to be ascertained, 

 may be counted perfect, if it be made to within one part in 

 two thousand. 



II. For temperatures between 0° and 50°, it is an easy 

 matter to keep the temperature of even such a simple bath as 

 the one given in figure I constant to within 0°*05 long enough 

 to adjust the apparatus and make several readings. By the 

 use of larger baths, or better still, of vapor jackets, the tem- 

 perature can be kept sufficiently uniform for the investigation 

 at different temperatures of most liquids. As a variation of 

 temperature amounting to 0°'l changes but little the readings 

 of the apparatus, it may be allowed that the temperature is, 

 for the purposes of this investigation, negligible. 



III. The possible error that may be committed in the read 

 ings of the apparatus can best be judged by considering the 

 readings themselves. A number of series of readings for dif- 

 ferent liquids at various temperatures are accordingly given 

 just as they were taken directly from the apparatus. These 

 readings are not to be taken as material for the calculation of 

 the surface tensions of the liquids, as in some cases they do 

 not represent the true distances between the lower extremities 

 of the capillary tubes, the position of these having been 

 altered purposely several times. The unit of a reading is a 

 fortieth of an inch. 



Nitroethane at 16°-95 



Nitroethane at 46°-6 



Tubes A and B. 



Tubes A and B. 



23-27 



21-23 



23-26 



21-26 



23-28 



21-21 



^itromethane at 24°-5 



Nitrom ethane at 41°- 



Tubes A and B. 



Tubes A and B. 



24-28 



22-86 



24-26 



22-87 



24-23 



22-80 



24-25 



22-81 



24-29 



22-85 



24-26 





24-26 





Benzene at 20°-0 



Benzene at 20"'-5 



Tubes A and B 



Tubes A and B. 



22-86 



30-55 



22-88 



30-54 



22-85 



30-49 



22-86 



30-56 



22-87 



30-55 



