176 
thickness the values of the surface tension calculated by equation (1) are 
quite concordant. In the article already referred tc the author gives re- 
sults for frames ranging in thickness from .0013 cm. to .02067 cm., the 
greatest variation being less than six-tenths per cent. Equation (2) 
gave results with a maximum range of four per cent. the difference be- 
ing greatest for thick frames. But in practice it is not necessary to use 
thick frames. In the case of the variation of the surface tension with 
temperature all the measurements may be made with a single frame. In 
this experiment the frame was .0102 cm. thick and 6.642 cm. long. 
Ss 
gb 
. iS 
BASSAS 
ee 
14 = Tt Wt 
en | 
qa, 
Ce ee 
Mee tenia eee 
LLIZLILL ALLL \ LLLDELLLUTTLLT HY 
Aise aitia 
Yi. 
p> 
Fig.2. 
Fig. 2 shows the arrangement of the apparatus for measuring the 
temperature coefficient of the surface tension of water between room 
temperature and 80°. A mica frame F was hung on a wire W attached 
to one arm of a balance—sensitive, at this load, to .002 mg.. The balance 
itself rested on a wooden box shown in section. This box had a door in 
front (practically air tight) with a double glass window through which 
the apparatus inside could be seen and the thermometers read. The 
wooden box enclosed a double walled tin box or tank T, with walls about 
