152 
of arbitrary degrees for a point at the top of a house in that city 
for all days in the years 1861-1870: 
Blocac Hnetiie Hae | Electric 
potential, intensity, potential, intensity, 
Month: Mont- St. Louis, eho ite Mont- St. Louis, 
souris. Mo. souris. Mo. 
SANUAITY; Heese sere ae 80 DOR Oly see Se ee ee eee 36 2.1 
Re bE at yi ee eee ee 68 9..9)|| “AT SUSE = te see a ee ane 50 238 
Marchie coca een tee noes 49 ieas||iSeptemberzsse2ese=se=ses 59 223 
Ny Ore Sete oe eee 41 0.6) || (OCto Dens sees ness = =e 65 5.8 
IN EN ee A eae Rca an 39 4.0)|| November =-=2ens=- see 73 8.0 
iUIN GC eee eee cee ae ae 39 2. December sess sse- 45-225 80 8.3 
These observations agree with those throughout the world in show- 
ing that the intensity is least in the summer seasons and greatest 
in the winter seasons of the respective hemispheres. There is also a 
corresponding slight diurnal-variation, in accordance with which 
the intensity at a given point 1s least at 3 p. m. local mean time. 
