containing his own six tracts, the other joining the last two, which are astronomical, with the astronomical epistle in question. Either of the first two hypotheses is credible enough. The third looks very unlikely. But it must be remembered that it is utterly imimpossible to enumerate the number of odd things which occurred in the first century of printing, before authors and publishers had fallen into a common understanding upon their modes of proceeding. Any thing imaginable may have taken place in one or more instances; and it happens sometimes that the unlikely thing, stated by a writer who is frequently inaccurate, turns out to be the truth, in spite of the more probable account of a generally more accuarte writer. And a strange assertion, which appears to be an obvious distortion of one which is known to be true, may nevertheless be one separate truth, with or without some admixture of the matter of the other. For instance, a poor authority on books, Granger, says that Roger Palmer, afterwards the notorious Earl of Castlemaine, husband to one mistress of Charles II., and ambassador to the Pope of James II., invented and wrote on a "horizontal globe." Now since John Palmer, in 1658, did certainly write on the 'Catholique Planisphær,' and since the phrase horizontal globe looks very much like an awkward rendering of the the word planisphere, we at one time took the liberty of thinking that Granger or another had confused the two Palmers; and we were not without our suspicion that the Catholic planisphere had perhaps assisted in the transfer of the book to a Catholic author. Nevertheless, we afterwards found (4) that Lord Castlemaine published in 1679, a work on what he called the 'English Globe.' Again, the rule of three, in middle Latin, is regula detri, so that, seeing Detri mentioned among arithmetical authors, we took it to be pretty certain that, as has sometimes happened, the name of a subject of a book has been substituted for
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