[2] Geoghegan's translation of the book, titled Dr. Esperanto's International Language, was published on January 17 [O.S.

[5] Unua Libro was also translated into Hebrew, Yiddish, Swedish, and Lithuanian in 1889 and then into Danish, Bulgarian, Italian, Spanish, and Czech in 1890.

To find some means of overcoming the natural indifference of mankind, and disposing them, in the quickest manner possible, and en masse, to learn and use the proposed language as a living one, and not only in last extremities, and with the key at hand.

In the next three parts, he addresses each difficulty specifically and explains why he believes Esperanto is fit to overcome them.

In part II, he demonstrates the ease of using Esperanto for international communication due to a simple and clear vocabulary.

[6] In part III, he presents an idea called the "universal vote", which is a campaign to allot 10 million signatures of people making the following pledge: "I, the undersigned, promise to learn the international language, proposed by Dr. Esperanto, if it shall be shown that ten million similar promises have been publicly given."

[5] Zamenhof received a wide range of reactions to Unua Libro, from mocking criticism to avid interest.

[8] In the hundreds of letters he received, he saw enough support to prompt him to publish Dua Libro in January 1888 and La Esperantisto in 1889, in order to provide more Esperanto reading material for those with interest.

Among the early supporters were educated Russian and Polish Jews, Leo Tolstoy and his followers, Eastern European freemasons, and speakers of Volapük who had lost hope in their language.