Finding Katahdin Document Packets, Chapter 4, Section 2
Chapter 4, page 106.
Large land-owners, or proprietors, used depositions to prepare cases against squatters who believed that if they improved or farmed wild land they were entitled to own it.
The proprietors believed that they owned the land and were entitled to payment. A deposition was essentially a local person's word that the land existed as stated in the proprietor's deed.