To J.J., who inquires about "_Whelps_," and refers to Howell's _Letters_, sect. 5 p. 9, I beg leave to suggest more precision in his future references. The passage is in one (viz. the viii.) of the 42 letters of the 5th section; but in the last and best edition (Lond. 1754) it is p. 204. I note this to inculcate the necessity of accurate references and mention of the edition quoted. As to the query itself, I can answer that the "_whelps_" were a class, perhaps I might say a _litter_, of light men-of-war of the fifth rate, which were so called, perhaps, after one named the "_Lion's Whelp_," in Queen Elizabeth's navy, and distinguished by numbers, as "_1st Whelp_," "_2nd Whelp_," and so on to at least "_10th Whelp_," which is to be found in a list of the navy in 1651. She was of 180 tons, and carried 18 guns and 60 men. It seems not easy to account for this class of vessels having been rated so high as 5th rates, but I suppose they were a favourite and favoured class. In reference to the discovery of America by Madoc, pp. 7 12 25 57, it may amuse your readers to be informed that Seneca shadows forth such a discovery:-- "Venient annis sæcula seris Quibus Oceanus vincula rerum Laxet, et ingens pateat tellus, Ichthysque novos deteget orbes; Nec sit terris ultima Thule." _Medea_, act ii, ad finem, v. 375. "A vaticination," says the commentator, "of the Spanish discovery of America." It is certainly a curious passage. C. * * * * * QUERIES. BERKELEY'S THEORY OF VISION VINDICATED. In Mr. Dugald Stewart's _Dissertation on the Progress of Metaphysical Philosophy_ he says of Lord Shaftesbury's work entitled _Characteristics_-- "It seemed to have the power of changing the temper of its critics. It provoked the amiable Berkeley to a harshness equally unwonted and unwarranted; while it softened the rugged Warburton so far as to dispose the fierce, yet not altogether ungenerous, polemic to price an enemy in the very heat of conflict." To this passage is appended the following note:-- "Berkeley's _Minute Philosopher_, Dialogue 3; but especially his _Theory of Vision Vindicated_, London, 1733 (not republished in the quarto edition of his works), where this most excellent man sinks for a moment to the level of a railing polemic." Can you or any of your readers do me the favour to inform me whether the tract here referred to has been included in any subsequent edition of the Bishop's works, and, if not, where it is to be met with? B.G. * * * * * DR. JOHNSON AND PROFESSOR DE MORGAN.