The thermometer in our underground room stood at 78 degrees of Farenheit, but we could not reduce the moist bulb below 49 degrees; nor was I surprised at this, considering we had not had rain for nearly four months, and that during our stay at the Depot we had never experienced a dew.

The ground was thoroughly heated to the depth of three or four feet, and the tremendous heat that prevailed had parched vegetation and drawn moisture from everything.

In an air so rarified, and an atmosphere so dry, it was hardly to be expected that any experiment upon it would be attended with its usual results, or that the particles of moisture so far separated, could be condensed by ordinary methods.

The mean of the thermometer for the months of December, January, and February, had been 101 degrees, 104 degrees, and 101 degrees respectively in the shade.

Under its effects every screw in our boxes had been drawn, and the horn handles of our instruments, as well as our combs, were split into fine laminae.