Abacuses; accounting machines; accumulator boxes; accumulator jars; accumulators electric; accumulators electric, for vehicles; acid hydrometers; acidimeters for batteries; acoustic conduits; acoustic couplers; acoustic (sound) alarms; actinometers; adding machines; aerials; aerometers; electronic agendas; air analysis apparatus; alarm bells, electric; alarms; fire alarms; alcoholmeters; alidades; altimeters; ammeters; amplifiers; amplifying tubes; amplifying valves; amusement apparatus adapt...