Double Contact Morse Code Key Face Size_26mm Pascal's-law apparatus on a 10

Pascal's-law apparatus on a 10 by 7 inch base with four interchangeable vessels screwed into a lever-pointer aperture whose rubber diaphragm displays pressure on a vertical index scale

5 mL in a two-tier stackable frame

Four 50 gram brass slotted masses paired with a 50 gram hanger

Long-focal double-concave glass lens at 75mm diameter and 300mm focal length

the universal gate from which any other Boolean function can be built in digital-electronics work

Double Contact Morse Code Key Face Size_26mm Pascal's-law apparatus on a 10Two armed Morse code contact key with a press knob over each spring arm, sized for paired station telegraph demonstrations where one key sends and the other relays back.