Duvernoy The School of Mechanism for the Pinoforte Op.120 by Jean Baptiste Duvernoy 

fifteen studies to precede Czerny's school of velocity 

Le Couppey L'Agilite Twenty -five Progressive Studies for Mechanism and Light Touch for the Pinoforte by Felix Le Couppey 

measures 12.25" x 9.25'

Preowned in acceptable condition - covers have been written on and do have some wear and bit dirty - many pages are written on but are in good condition