Consider this a Directory Day coda: check out The International Genealogical Directory, 1907 compiled by Charles A Bernau, of Bernau Index fame. The digitized version is on the Internet Archive via the Allen County Public Library.
Bernau wrote 7,200 letters and received 1,387 responses resulting in entries in this directory, plus a few unusual responses on which he comments in the opening pages.
The volume is in six Parts.
1. Names and addresses, and sometimes interests, of nearly 1.400 genealogists, both amateur and professional, the majority residing in Britain and the US, but also Australia, Canada, New Zealand, South Africa and elsewhere.
2. Surnames of nearly 4.500 families, about which those who are named in
Part I. either possess or desire information.
3. Nearly 300 "Genealogical Queries and Memoranda."
4. The Antiquarian Societies of Ireland, the North of France, and the Channel Islands, with a list of the Officers of Arms for the United Kingdom.
5. Particulars of a few publications of which their respective authors
have surplus copies to dispose in exchange.
6. A list of privately-printed Family Histories and Pedigrees received from January 1, 1905 to the printing deadline.