Abstract Mr. Hoiland was a North Dakota inventor. The collection contains various United States and foreign patents and promotional material for some of his inventions including wild oats separator (most extensive), valves, lignite grate, freight car door, flying machine (helicopter), cow trainer, car guide, and fan for explosive engines.

Abstract Correspondence, legal material, and Canadian patent relating to Skogman's invention of a header and binder attachment for traction engines.