and 32 respectively which serve as guide members and bearing surfaces as the tool 10 is lowered or raised through a bore hole or hollow drill bit in a bore hole as desired referring to fig2 and 3 the putty cup 18 includes a blade end 34 for engaging a core the putty cup 18 includes putty 36 and grooves not shown on its interior surface 38 the exposed surface 35 of the putty 36 is well oiled the upper end 40 of the putty cup 18 opposite the blade end 34 includes circumferential threads 42 a plug member 44 having a lower threaded surface 46 with circumferential threads 48 mates with circumferential threads 42 of the putty cup 18 circumferentially mounted about the plug member 44 is the bushing 30 preferably made of nylon the plug member 44 includes an upper end 50 the upper end 50 includes upper threaded surface 52 with circumferential threads 54 arranged therein adjacent the lower ends of the threads 54 is an o ring groove 56 for receiving an o ring 58 the upper end 50 of the plug member 44 includes a recess 55 for receiving a mark receiving member shown as scribe receiving cylinder 59 preferably formed of plexiglass the elongate body member 10 includes a lower threaded portion 60 having circumferential threads 62 arranged therein the circumferential threads 62 mate with threads 54 in the.