Mechanical Stop Watch, 1/10 Second Subcategory_Boiling Flasks this Brownlee-pattern apparatus gives a

this Brownlee-pattern apparatus gives a clean visual proof of the 2:1 stoichiometry of water decomposition

Double-walled copper-cylinder hypsometer at 34 by 6cm on a steam boiler

collecting water displaced by a submerged object for volume calculation in Archimedes-principle demonstrations

well suited to demonstrating the force on a current-carrying conductor in a magnetic field

separation

Mechanical Stop Watch, 1/10 Second Subcategory_Boiling Flasks this Brownlee-pattern apparatus gives aBattery free analog mechanical stopwatch reading to one tenth of a second, providing repeatable timing for physics classroom demonstrations and student laboratory experiments without power.