Boyles-Law-Apparatus-RVFM-PH10615-P-This-advanced-Boyle-s-Law-apparatus-is-designed-to-give-a-more-accurate-demonstration-of-the-elasticity-of-gases-The-apparatus-gives-accurate-readings-over-a-wide-range-of-pressures-P-P-Two-glass-tubes-one-with-a-closed-top-&-one-with-an-open-top-run-parallel-to-one-another-on-metal-rods-&-are-connected-together-by-a-piece-of-flexible-tubing-This-allows-one-of-the-tubes-to-be-raised-higher-or-lower-than-the-other-&-then-locked-in-place-P-RVF