This is lesson 1 of the volume:"First Steps at the organ"
This book is not really a method for learning how to play the organ, but a collection of easy pieces for novice organists.
The book is divided into 10 chapters ("lessons"), each chapter presenting a brief description of an organ stop among the stops that are most often encountered on a large number of instruments.
The 10 small pieces offered are specially written to introduce the organist to the particularities of the stop that is the subject of the study.
From the difficulty point of view, the 10 pieces, with the exception of short passages, are written for 3 voices, with notes in long values at the pedalboard.
The modes of the pieces alternate between minor and major, with tones whose key signature goes progressively from no accident to 2 sharps or 2 flats.
In the first Comment I give the description of lesson 1
The book is available at http://www.lulu.com/shop/jean-paul-verpeaux/premiers-pas-a-lorgue/paperback/product-24412157.html