REMOVE

1. Nitrate negatives
2. negative
3. Show jumping.
4. between 1933 and 1942

WHAT

1. Horse shows. (1)
2. Nitrate negatives (1)
3. Photographs (1)
4. Show jumping. (1)

WHO

1. Genthe, Arnold (1)
2. Library of Congress Print … (1)

WHEN

1. 1869-1942 (1)
2. 1933 (1)
3. 1942 (1)
4. between 1933 and 1942 (1)