I have that book, and although it does indeed provide excellent explanations
of the workings and design of rotary engines, it is not that useful as a
modelling reference. For example, there is a chapter on the Clerget engines,
but it lacks any photographs whatsoever. The single photgraph included of the
Bentley engines is that of a 200hp shown from an extreme angle. Similarly,
there is only a single photgraph of a Lerhone engine, and it is of the
two-row 120hp version.
Heck I don't even know what planes actually used a two-row LeRhone.
In other words, don't get weepy-eyed if you thought this out of print book
was a Holy Grail of reference photographs;-)
Jay vossman@cris.com