This is a new edition of Max Talmey's short textbook on the international auxiliary language Ido. Originally published in 1919, to the best of my knowledge it is in the public domain in all jurisdictions.
A pre-compiled PDF is available included in this repository as talmey1919.pdf. Scans of the original print edition are also included, as scans.pdf.
I have done my best to follow the formatting and style of the print edition in most respects, though not religiously. The content is essentially unaltered except to correct clear errors (and no doubt introduce new ones).
The student of Ido should keep in mind that this work represents one prominent Idist's view of the language as it existed just prior to the First World War; in some respects it differs from what would be considered correct today. Talmey's English usage here is also markedly old-fashioned.
If you are interested in learning Ido, I recommend Gilles-Philippe Morin's edition of Kompleta Gramatiko Detaloza.