1. AN APPARATUS FOR MEASURING THE TENSILE STRENGTH OF MOLDING SAND, SAID APPARATUS COMPRISING A MEASURING HEAD HAVING A RECESS FOR RECEIVING AND RETAINING A PORTION OF A BODY OF SAND TO BE TESTED, A PULL ROD COUPLING MEANS FOR RELEASABLY CONNECTING ONE END OF SAID PULL ROD AND SAID HEAD, A PISTON ON THE OPPOSITE END OF SAID ROD, A CYLINDER SLIDABLY RECEIVING SAID PISTON, A COMPRESION SPRING FOR BIASING SAID PISTON INWARDLY OF SAID CYLINDER, MEANS FOR ADMITTING AIR PRESSURE TO SAID CYLINDER AND A PRESSURE INDICATOR CONNECTED TO SAID CYLINDER, WHEREBY UPON ADMISSION OF AIR PRESSURE TO SAID CYLINDER TO MOVE SAID PISTON AND ROD OUTWARDLY AND COUPLING OF SAID ROD TO SAID HEAD, SUBSEQUENT RELEASE OF PRESSURE FROM SAID CYLINDER WILL PERMIT SAID SPRING TO MOVE SAID PISTON AND ROD INWARDLY TO MOVE SAID HEAD AND SEPARATE THE SAND THEREIN FROM THE BODY OF SAND, THE AIR PRESSURE AT THE INSTANT OF SEPARATION OF SAID SAND PROVIDING AN INDICATION OF THE TENSILE STRENGTH OF THE SAND.