Students looking at the piles of books strewn over my desk, my windowsill, my bookshelves and my floor sometimes understate things a bit and say, “You have a lot of books”. (One reason I don’t really want to move again, ever, is not just so I can avoid packing them but also so I can avoid the accusatory glare from movers.)
One thing I sometimes say in reply is, “Well, they’re the tools of my trade”. Truth to tell, there are some on the shelves that I haven’t opened in years, and maybe a few that it’s likely I’ll never open again. However, if they’re involved in my teaching in any manner, I tend to look at them a lot.
I’m guessing that many academics have a class of books that they frequently consult while preparing lectures or thinking about class discussions: books that concern areas of specialized knowledge that are not quite directly your own field but are quite close to it, that read very plainly and clearly, and that make minimal arguments or are theoretically unadorned while being informationally dense. Textbooks for specialists might be the best way to think of these works.
The Birmingham and Martin anthology is a great example of this kind of book. When I’m teaching precolonial Central Africa, I often pull it off the shelf to refresh my knowledge and prepare my lectures. I’m not familiar enough with various precolonial states or peoples in the region to rattle off details about them intuitively: keeping Fang, Azande, Mangbetu and so on clear from one another is important but I really have to get a refresher every couple of years. (Whereas most southern African states and ethnonyms I know without review because I make use of that history in my own writing as well as in teaching.)
Once upon a time, I’m sure that the editors and publishers of this volume and its companion modern volume hoped it might be adopted for undergraduate use. Maybe it was when it was in print. I haven’t used it myself as an undergraduate reading, because I think you need to know quite a lot before reading it to make good use of what it has to say. It has the problem that a lot of Africanist writing has when it comes to communicating with non-specialist American or European audiences: little or no prior experience with the subject matter makes retaining names, details, and places very difficult.
It is the kind of writing that I think specialists should be writing for other specialists, though: a concise review of specialized knowledge about some basic or fundamental subject area. Effectively, a high-level Wikipedia, written just for us. No intent to resolve major disputes or stake an original claim (though all the authors in the Birmingham and Martin volume were picked because at the time, they were known as scholars who had made original research findings about the history of particular regions or states within Central, East and Southern Africa).