The book is half a way between science philosophy and physics; in fact E.March was a remarkable thinker of nineteenth century who was the principal promoter (jointly with Avenarius) of the Empirio-Criticism theory regarding the ways our scientific knowledge is conformed from sensations coming from the physical experience.
The book contains three articles published previously and separately and joined together for the occasion; the three as a whole explore several aspects of the relationships between spatial physical sensations and the development of geometric ideas and theories. So to say, the simple proposition that spatial sensations are elaborated in our consciousness to distillate geometric objects is worked out here and there, highlighting every time different topics of the subject which makes the book an interesting conglomerate of subtle insights about how our brain perceives and imagines the physical space and builds geometric theories. It contains also a short account of the historical development of non-euclidean geometries. (Several of the book's ideas are developed in a deeper way in the previous book "Analysis of the Sensations" by E.Mach itself).
At the end of the book Mach writes an impressive paragraph:
"But the physicist can derive in another direction substantial assistance from the labours of geometers. Our geometry refers always to objects of sensuous experience. But the moment we begin to operate with mere things of thought like atoms and molecules, which from their very nature can never be made the objects of sensuous contemplation, we are under no obligation whatever to think of them as standing in spatial relationships which are peculiar to the Euclidean three-dimensional space of our sensuous experience. This may be recommended to the special attention of thinkers who deem atomistic speculations indispensable."
Written about 1900, it announces the turn that physics was to get several years later. Take this example as a measure of the stature of Mach as natural philosophy thinker.
If you are interested in science philosophy and physic history this is an excellent piece for your library.