One of the most beautiful little books ever issued from the Elzevir or any other press is the _Caesar_ of 1635, which, on referring to the table, we shall see must have been printed by Bonaventure and Abraham at Leyden.[11] It is in 12mo, and there are no less than three editions, the first and second being so much alike that no one could detect the difference without the most careful of careful inspections. The "right" _Caesar_ is the first, and may be recognised from the Buffalo's Head on a scroll at the head of the dedication. Pages 149, 335, and 475 are misprinted 153, 345, and 375 respectively in the first edition, and there are 35 lines to the page. The second edition, which has not, pecuniarily speaking, a tenth part of the value, has 37 lines to the page, and the misprints are corrected. Another fine work, the _Comediae_ of Terence, Leyden, 1635, 12mo, passed through five editions, all of which are very much alike. The first and "right" edition has, however, on page 51, the word _laches_ printed in red, while page 101 is improperly numbered 69. In the second edition _laches_ is in black, in the fifth it changes to red again, so that the greatest caution has to be exercised lest the first and fifth editions should be confounded. The former is worth much more than the latter, as the unfortunate purchaser will find to his cost when he comes to sell again. As previously stated, the "good dates" begin from 1625, the year when Bonaventure and Abraham went into partnership at Leyden, and any books dated from that year to 1655, when Jean and Daniel dissolved partnership, are most likely to be of value, provided only the right edition is forthcoming. Daniel was, however, by far the best printer in the family, though some make an exception in favour of Bonaventure and Abraham; and as he continued in business at Amsterdam, either by himself or in conjunction with Louis from 1655 to 1680, those dates must also be considered "good". From the Amsterdam press, in 1655, issued that prize of Elzevir collectors, the _Pastissier Francois_, and the splendid _Virgil_ of 1676 in _grand_ as well as _petit format_, or as we should say in English, on large and small paper. The halcyon days of the press at Leyden date from 1625 to 1655; those of the press at Amsterdam from 1655 to 1680. It is, of course, impossible for anyone, be he dealer or amateur, to carry in his head all these details and distinguishing marks, and reference in cases of doubt will have to be made to Willem's _Les Elzevier_, a work which has superseded all others on the subject. With this book at hand it is difficult to go wrong, as the minutest points of difference are chronicled with great fidelity.