Original oil and gas trade magazine vintage ad for CORE LABORATORIES, INC., of Dallas, TX. Petroleum Reservoir Engineering. Out for A Spin at 6500 RPM. Core Lab's Research and Development Department accepts not only the new and unique problems of reservoir behavior but also maintains a constant program of improving its own standardized techniques and procedures. Unique 1955 old oilfield petroleum drilling industry magazine advertisement. Nice graphics. On the reverse side is a fractional page ad for HARBISON-FISCHER MANUFACTURING COMPANY of Fort Worth, TX. Best Pump in the Oil Patch. Harbison-Fischer DuMore Balls and Seats. Unique 1955 petroleum industry advertisement. Approximate page size 9 x 12 inches.