Newly liberated into the public domain, the Encyclopaedia Britannica 1926 supplement in three chunky volumes. They form “an entirely new survey of the march of events”, as the Preface has it.
These became the latest supplement to the 11th edition, and they provide a useful updating and snapshot of various emerging fields as they were understood in the ‘prime Lovecraft years’ of 1910-1926 (the dates given in the Preface). Lovecraft owned the 9th edition (1875-89), and its “A Guide to Systematic Reading In…”, the 9th edition being especially revered for its very high standards of scholarship. The dates of the 9th may seen antediluvian to us, but on most matters he was only about 20-25 years behind the current volumes… until 1926. Presumably for more modern topics he was able to consult the latest edition, and its most recent supplements, at the Public Library in Providence or New York City.