What is an alta edition of a book?

Alta from the Latin Alpha meaning first. Alta Edition means Edition A or First Edition.

Porter & Coates, a Philadelphia publishing house, published a series of books between 1870 and 1890, which they called Alta Editions. Not one of them was a first edition. All of them were reprints of books published by other publishers years before. For instance, the Alta Edition of De Foe's Robinson Crusoe came out in 1890. The first edition dates to 1719.