@Roberta,
You're giving me the feedback that I want.
If I don't have an agent, how would I know whether the contract I am given is fair or whether I should seek or avoid some contract feature in particular?
Roberta, in science and math, there are many books that are not necessarily for a course, but that people working in that area buy in order to learn something that they need or want to know. I personally have bought perhaps hundred such books in my life. People in the sciences or math are usually in those fields because they have a passion for them and often buy books just because they want to know something. While my book could be used for a one semester course, it is slightly under 200 pages long. It really is more like a monograph.
I don't want to be specific, because, should it be published, I don't want anyone on A2K to use the details to find my identity. I can say that it is about a prominent, and not esoteric, area of higher math used constantly in science and engineering. At this point, you may be thinking that if it is such a prominent area of math, it has been covered a thousand times, and that is correct. The thing is, though, that all of the treatments are more or less identical and about two or three dozen pages long. I have covered it in a depth which I have never seen in any published work, and I did search a university library when I started writing it. In some cases, I had to figure out the techniques myself because I had never seen them covered.
Let's put aside questions about publishability. You seem to be saying that I should write queries directly to publishing companies? Again, how would I know if a contract is fair?