Franklin's pulse glass: Two glass bulbs and tube containing ether.

4C33.50 • C+70+45

diagram for demo

Franklin's pulse glass: Two glass bulbs and tube containing ether. The apparatus consists of two glass bulbs, with a glass connecting tube, containing ether. The glass vessel is supported on a pivot at the center of the connecting tube. The lower bulb is thus positioned near a small electric heater. The warmth from the heater causes rapid evaporation of the ether in the bulb close to it, and this produces sufficient pressure to force liquid into the higher bulb on the opposite side. The heater at the opposite side now warms ether as the vessel tips to the opposite side. The motion continues to recycle. TEMPERATURE AND EXPANSION

Related Demos

C+70+0 Galileo's air thermometer forces liquid down when heated. C+70+5 Heated iron wire stretches, rotates pointer. C+70+6 Heated horizontal nichrome wire stretches, weight sags. C+70+10 Heated steel rod expands, raises pointer,breaks pin on cooling. C+70+15 Ring and ball: Ball fits through ring only after ring is heated. C+70+20 Ice bomb: Iron sphere ruptured by freezing water. C+70+22 Heating a rubber band: negative coefficient of thermal expansion C+70+25 Cubic coefficient of expansion: Dissectable wooden cube. C+70+30 Steam gun: Friction heated water in tube shoots a cork. C+70+32 LN2 in a model cannon shoots a cork. C+70+35 Bimetallic strip: Brass/invar strip curves when heated. C+70+40 Bimetallic switch: Change in temperature lights cold/hot lamps. C+70+47 Dippy bird: Large glass bird containing ether oscillates. C+70+50 Piston and cylinder compress/expand air measuring temp. and pressure. C+70+55 Fire syringe: paper is ignited in a cylinder with a piston. C+70+60 CO2 fire extinguisher: Expanding gas freezes into snow. C+70+65 Cooling by expansion: Jar with water compressed with air. C+70+70 Hot water geyser, runs 5-10 min. C+70+75 Boyle's Law: At constant T, Pressure times Volume is a constant. C+70+80 Gay-Lussac's Law: At constant V, Pressure is proportional to Temperature. C+70+85 Charles' Law: At constant P, Volume is proportional to Temperature. C+70+90 Grain Silo explosion: A cloud of power is ignited and blows lid off of can.