Plate 5-8 of 1921 cloud chart. 5. Cirrus (top half of picture) and cirro-
stratus (bottom half). 6. Cirrus merging into cirro-stratus: not infrequently
a sky aspect subsequent to (2) or (4). 7. Cirro-stratus and alto-stratus, with
cirro-cumulus and alto-cumulus tops... 8. Cirrus (the detached portions) and
cirro-stratus, from evaporation of such clouds as (7).