mnemometer vs memory apparatus

mnemometer and memory apparatus both are nouns.

Word	Noun	Adjective	Verb	Adverb
mnemometer	Yes	No	No	No
memory apparatus	Yes	No	No	No

As nouns, mnemometer and memory apparatus are synonyms defined as:

mnemometer and memory apparatus: An outdated mechanical device used for presenting a series of stimuli to be memorized.

mnemometer (noun)	memory apparatus (noun)
An outdated mechanical device used for presenting a series of stimuli to be memorized.	An outdated mechanical device used for presenting a series of stimuli to be memorized.