REMOVE

1. sky
2. tools
3. rock
4. railroads

WHAT

1. black-and-white negatives (1)
2. exterior views (1)
3. farmers (people in agricu … (1)
4. farms (1)
5. hats (1)
6. silver gelatin (1)
7. snow (precipitation) (1)
8. storms (1)
9. tractors (vehicles) (1)
10. trees (1)
11. Visual Works (hierarchy n … (1)
12. winter (season) (1)

Less

WHEN

1. 1966 (1)