and probably more stages of condensation. Investigators into the phenomenon of cloud formation claim to have ascertained that the first effect of condensation is to form little globes o

er or smaller according to the rapidity of condensation. There is probably another power at work to prevent the too ready precipitation of moisture when condensed, and that is the wind. A cloud never stands still, although in some cases it may appear to do so. If we take a stone in our hand and allow it to drop without applying any force to it, it will fall directly to the ground. But if we give it

mulus, or heap-cloud. If there were no air currents this billowy cloud would stand as the capping of an invisible pillar of ascending vapor, but as it is never the case that air is not moving at some velocity in the upper regions, it floats away as rapidly as it is formed. This peculiar kind of cloud is formed in the mid-regions of the atmosphere, and it is a summer cloud as well as a land cloud. Of course, it may float off over the ocean and maintain its peculiar shape for a certain distance, but it is rare that such a cloud would ever be seen in mid-ocean or in

ture, it would not condense into cloud. Clouds may be absorbed into the atmosphere-or evaporated-and become invisible; and this process is going on to a greater or less degree continually. If we watch the steam as it escapes from a steam boiler, the first effect is condensa

ler, even on the hottest day, it is hotter than the surrounding air; the first effect is condensation, and then evaporation takes place the same

ndensation,-which would result in precipitation,-as the sun lowers in the west and the heated air becomes more evenly distributed this condensed vapor is reabsorbed into the air as invisible moisture by a process allied to that of evaporation. This condition of things would extend to a much longer period than it does in our latitude if it were

a. They are formed only at a season of the year when the atmospheric conditions are most uniform. At certain times of the day and night the moisture will rise to this height before it condenses and when it does condense it immediately freezes, which makes it take on these peculiar forms that would no doubt conform very closely to the frost pictures on the window pane if it were not for the disturbing influences of air currents at this altitude. The fact that they are ice or frost clouds instead of water clouds gives them that peculiar whiteness and brightness of a

ogs prevail when the barometer is low. As soon as it rises from the source of evaporation the moisture condenses almost to the point of precipitation. There is no

s it further descends it takes on a different form called the cirro-cumulus, or curl-heap. This is just the opposite in its appearance to the cirro-stratus, as it is broken up into flocks of little clouds separated from each other and in the act of changing to the form of the cumulus, or billowy form of cloud; and this latter takes place when it drops to a still lower stratum of warmer air an

r globules collapse and a number of them run together, forming a solid drop of water, and here it begins to fall. It may be very small at first, but in its fall other con

ow smaller by absorption into the thirsty air, and will not be allowed to reach the earth. Often there are showers of rain in the air that fall

ay in summer there appears above the peak of Mount Blanc a beautifully formed cloud cap standing some distance above it and hollowed out underneath like an inverted cup. Although this cloud appears to be stationary, it is undergoing a rapid change; the moisture rises from the snow-capped peak as invisible vapor to a certain distance, where it is condensed into a cloud of wonderful brilliancy. As the cloud glo

erstorm may be in progress far below us, while the sun may be shining from a clear sky above, with pe

moisture is distributed over large areas by these rain clouds being borne on the wings of the wind; an