I'm wondering who exactly the target audience was. School children? University students? The general reading public?
And yeah for sure it is propaganda. It is clearly trying to tell a pretty standard colonialist narrative that "Africa is a lovely place, too bad the Africans couldn't get their act together. It's OK though, the friendly, altruistic Europeans are here to educate and civilize the locals".
It is hoped that this book and its companion volume dealing with non-African peoples will be the beginning of a series of simple, readable accounts for Africans of some of the various objects of general interest in the world of to-day. There are many such works published for the use of English and American children. But the native African has a totally different experience of life, and much that is taken for granted by a child of a Northern civilized land needs explanation to one used to tropical uncivilized surroundings. Again, the African knows the essential operations of everyday life in their simplest form, whereas the European knows them disguised by an elaborate industrial system. All this makes books written for English children almost unintelligible to a member of a primitive race.
Why do you call it propaganda, comprehensive propaganda no less, without having seem to have even read it very closely?
People just seem to be having this knee-jerk reaction to it in order to signal their adherence to the modern Regressive dogma.