Cirrus, Cumulus and Stratus clouds

1376. The simple modifications are thus named and defined: - 1. Cirrus, a parallel flexuous, or diverging fibre, extensible in any or in all directions (fig. 245. a.); 2. Cumulus, a convex or conical heap, increasing upwards from a horizontal base (b); 3. Stratus, a widely-extended, continuous, horizontal sheet increasing from below (c).