- A device that converts sound into an electrical signal - Chopin more confused by voice projector - Device used when addressing a crowd - An instrument for intensifying and making audible very
feeble sounds. It produces its effects by the changes of intensity in
an electric current, occasioned by the variations in the contact
resistance of conducting bodies, especially of imperfect conductors,
under the action of acoustic vibrations.
- Lead monoxide; a yellowish red substance, obtained as an
amorphous powder, or crystallized in fine scales, by heating lead
moderately in a current of air or by calcining lead nitrate or
carbonate. It is used in making flint glass, in glazing earthenware, in
making red lead minium, etc. Called also massicot.