I have a book it seems quite old and is in reasonably good condition.

British Orchids - How To Tell One From Another
By Colonel J S E Mackensae
Illustrated by Miss A Talbot, Ponsonby
Printed and Published by Unwin Brothers, 27 Pilgrim St, London

Unfortunately I do not have a date of publication, but if anyone can give me
any information about it and if it has any value I would be very grateful.