38 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 
the number of seconds of the shoot from s to s’ and in the hour 
and minute of the observations. They differ, of course, as to 
the stars in the lines of sight from stations thirty-five miles 
apart. The averages of the time from gs to s’ and of the time 
(Selr.0.) (Wake Forest) 
of observation, as noted, are taken as correct; 6 seconds as the 
time of transit and 8 hours 29 minutes 30 seconds as the time 
of observation. 
These simple observations are sufficient. The rest is matter 
of calculation aided by data taken from the American Eph- 
emeris, a government publication based on the work of the 
National Observatory at Washington. 
Skilful use of the data for Castor and Capella, a Hydre and 
Procyon, gives the directions of those particular stars as seen 
from Land W at 29 minutes and 30 seconds past 8 o’clock on 
the evening of May 1; that is, the directions of s and s’ from 
L, and their directions from W. 
In Fig. 2, p and p’ are points on the earth vertically under 
s and s’.. The directions found by calculation as just stated, 
are: for s, its angles of elevation pls and pWs, also its hori- 
zontal bearings, the angels pLS and pWS; and for s’ the like 
angles p’Ls’, p’ Ws’, p’LS and p’WS. Obviously, this gives 
all the angles of each of the three triangles which meet at p and 
of the three which meet at p’. And since one side, LW, is 35 
