Again I returned to the camp in time for a final and completely satisfactory series of observations on April 7 at noon, Columbia meridian time.

These observations gave results essentially the same as those made at the same spot twenty-four hours before.
I had now taken in all thirteen single, or six and one-half double, altitudes of the sun, at two different stations, in three different directions, at four different times.

All were under satisfactory conditions, except for the first single altitude on the sixth.

The temperature during these observations had been from minus 11 deg.

Fahrenheit to minus 30 deg.