receives and locates both lower and upper terminal and it provides easy control of the amount and positioning of sealant 4 the underneath portion of the rim guides and receives terminal 2 the upper portion guides and receives terminal 3 terminal 3 is in cross section shaped generally like a hat with a brim or rim portion in a horizontal plane in fig1 with the crown or head cavity portion opening to the bottom and with the sidewalls of the cavity portion angled steeply as for example the 90 u00b0 shown to the rim portion the flat part at the top connecting the cavity wall is the top closure operation of the invention is shown by comparing fig2 with fig3 since terminals 2 and 3 and pool of conductive liquid 5 are all conductors and insulating spacer 1 is an insulator the gap all around the uniformly bulged shape of 5 indicates 2 and 3 are electrically separate in fig2 when the invention is tilted as in fig3 the shape of 5 becomes unsymmetrical axially or bellied and the belly portion extends far enough radially to touch the wall of the cavity in 3 making electrical contact and closing the switch touching the wall of the cavity to make electrical contact reflects the preferred embodiment any conductive ring surrounding mercury pool 5 and electrically connected to an external terminal will serve as in internal terminal obviously returning the switch somewhat toward the horizontal will cause the bellied portion of 5 to pull free of the wall and will open the switch the difference between the 34 make 34 angle and the 34 break 34 angle is hysteresis which is expected to be.