Single Contact Morse Code Key Base_Octagonal these concavity microscope slides hold

these concavity microscope slides hold liquid samples for hanging-drop preparations and observation of specimens in suspension

showing the hexagonal bonding within each layer and the weak bonding between layers

Plated spring arm with press knob and a single contact stud

supporting up to three pendulums simultaneously for harmonic-motion work

and storage between uses at the laboratory bench

Single Contact Morse Code Key Base_Octagonal these concavity microscope slides holdPlated spring arm with press knob and a single contact stud, configured to make and break a circuit at the rhythm of a Morse code transmission for telegraph history demonstrations.