Lecture on Clouds.

Mr. R. DeC. Ward gave an interesting lecture last night before the Natural History Society. He talked a few minutes about the main features of cloud formation, and then showed by means of lantern slides a very fine series of cloud views taken from photographs. Clouds, said Mr. Ward, are formed by the cooling and condensation of vapor in the air. There are three different types which are classified roughly into three kinds, the cirrus, characterized by its swift motion and feathery appearance; the cumulus, composed of round heaped-up masses; and the stratus, or low ground clouds, such as rise from valleys at night.