There are 10 Rock Carvings that can be found once Chapter 2 starts. You can find up to nine of them without having met Francis Sinclair, but you must meet him to gain access to finding all 10 of the Rock Carvings. Once you have found all of the carvings, head to any post office and mail them. After a few days, you will receive a letter inviting you back to the same cottage for another meeting with Frances. After that encounter, re-enter the cottage and pick up the Old Brass Compass.