Original oil and gas trade magazine vintage ad for BAROID SALES COMPANY. Main office and factory was located in Los Angeles, CA. Tulsa, OK and Houston, TX. Cretaceous Times was beginning of Bentonite with Volcanic Ash. Today Aquagel is the Ideal Drilling Clay. This unique 1936 old oilfield petroleum drilling industry magazine advertisement would display beautifully matted and framed. Great graphics.