Combination Dark Chamber for Phototropism Experiments, 21 x 7 x 7" Subcategory_Condensers and apparatus in laboratory and

and apparatus in laboratory and demonstration setups

eliminating cord-threading during setup in compound-pulley experiments

and rolling-motion experiments on inclined planes

Tangent-galvanometer instrument that derives current absolutely from compass-needle deflection against Earth's horizontal field

the low-mass vessel minimizing heat absorption during specific-heat experiments

Combination Dark Chamber for Phototropism Experiments, 21 x 7 x 7" Subcategory_Condensers and apparatus in laboratory andEnclosed dark chamber with directional light ports houses seedlings under controlled conditions for phototropism, etiolation, and light direction response experiments.