Geological Sketches, Bird's Skull

Black ink, gray wash, and graphite on cream antique laid paper

Watercolor, gouache, and graphite on cream wove paper

Graphite on cream modern laid paper

Brown ink over graphite on cream wove paper

Metalpoint on prepared paper

Brown ink and wash, white gouache over graphite on off-white wove paper

Watercolor, gouache, shell gold, and platinum paint on linen-covered panel prepared with zinc white ground

Pastel on board

Black ink and graphite on white paper

Graphite and watercolor on off-white paper

Red, brown, and white chalk on blue-green wove paper