The fact, however, turned out quite the contrary.

The hygrometer gave a difference of 29.6 degrees, between the temperature of the air, and the point at which dew was precipitated.

This difference was nearly double that which I had observed on the previous mornings.

This unusual degree of atmospheric dryness was accompanied by continual flashes of lightning.

Is it not an uncommon case, thus to find a remarkable degree of aerial transparency with such a state of weather?
Generally the atmosphere is hazy; and this is caused by the falling of impalpably fine dust, which was found to have slightly injured the astronomical instruments.