REMOTE-READING MICROMETERS; AN APPARATUS, CONSISTING OF A TANK GAUGER'S REEL AND TAPE WITH A METAL PLUMB BOB, AND A MILLIAMMETER IN THE CIRCUIT THROUGH THE PLUMB BOB AND TANK SO THAT THE MILLIAMMETER DEFLECTS WHEN THE PLUMB BOB PASSES THROUGH THE LINE OF DEMARCATION BETWEEN THE OIL AND THE WATER IN THE TANK, AND USED FOR INDICATING SAID LINE; AND SPECIFIC GRAVITY METERS