What is an instrument used for double writing, as one for producing embossed writing for the blind and ordinary writing at the same time. -- Dip`lo*graph"ic*al (#), a. -- Dip*log"ra*phy (#), n called?

diplograph — An instrument used for double writing, as one for producing embossed writing for the blind and ordinary writing at the same time. -- Dip`lo*graph"ic*al (#), a. -- Dip*log"ra*phy (#), n. (Webster's 1913.)