Plate 30.

MACKEREL SKY.

(Alto-stratus Maculosus.)

Plate 30.

MACKEREL SKY.

(Alto-stratus Maculosus.)

A lower and coarser form of the spotted alto-stratus is shown in Plate [31], where it is seen through the gaps in a thin sheet of broken stratus. In this case also the sun was getting low in the sky, being hidden by the denser bit of stratus in the bottom left-hand corner.