Base system of proper motions for the A GK 3R

An initial system of proper motions has been formed for the A GK 3R on the system of FK 4 using meridian circle catalogs whose observations included the use of screens and traveling wire micrometers, and whose reductions included variation of latitude. A system of 5590 proper motions resulted with centennial mean errors of 0.37 in right ascension and 0.40 in declination. Systematic effects such as magnitude equation have been investigated and found to be small.