There are six books on the use and setting of dividing heads.
These include in no order:

1. Hoffman,
2. Elliott,
3. Victoria,
4. WMW,v
5. The text out of an old 1900's book on Indexing and Dividing
6. British Cincinatti Book, possibly the best book ever printed on this subject

The British Cincinatti Book:

This runs into 110 pages and, as well as the use of the dividing head, also covers sections on cutting spur, bevel, helical and worm gears as well as other operations using a dividing head.
The Cincinatti book also covers the range of high division numbers that were unique to this company.