You were running a parallel circuit- - - - -the original ammeter had a better connection, probably one with lower resistance, so virtually all the current followed that path. Basic Ohm's Law! You would have to put both ammeters in series with each other for your test method to work.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!