Another caution should be given to well-meaning ignorance. Never produce that as an Irish bull for which any person of common literature can immediately supply a precedent from our best authors. Never be at the pains, for instance, of telling, from Joe Miller, a _good_ story of an _Irish_ sailor, who _travelled_ with Captain Cook _round_ the world, and afterwards swore to his companions that it was as flat as a table. This anecdote, however excellent, immediately finds a parallel in Pope: “Mad Mathesis alone was unconfined, Too mad for mere material chains to bind; Now to pure space lifts her ecstatic stare, Now running _round_ the circle finds it square.” Pope was led into the blunder of representing Mad Mathesis running _round the circle_, and finding it _square_ by a confused notion that mathematicians had considered the circle as composed of straight lines. His mathematical friends could have told him, that though it was talked of as a polygon, it was not supposed to be a square; but _polygon_ would not have rhymed to _stare_; and poets, when they launch into the ocean of words, must have an eye to the helm; at all events a poet, who is not supposed to be a student of the exact sciences, may be forgiven for a mathematical blunder. This affair of squaring the circle seems to be peculiarly liable to error; for even an accurate mathematician cannot speak of it without committing something very like a bull. Dr. Hutton, in his Treatise on Mensuration, p. 119, says, “As the _famous_ quadrature of the late Mr. John Machin, professor of astronomy in Gresham College, is extremely expeditious and _but little known_, I shall take this opportunity of explaining it.” It is to be presumed, that the doctor here uses the word _famous_ in that acceptation in which it is daily and hourly employed by our Bond-street loungers, by city apprentices, and men of the ton. “That was a _famous_ good joke;” “He is a _famous_ whip;” “We had a _famous_ hop,” &c. Now it cannot be supposed that any of these things are in themselves entitled to fame; but they may, indeed, by the courtesy of England, be at once _famous_, and but little known. It is unnecessary to enter into the defence either of Dr. Hutton or of Pope, for they were not born in Ireland, therefore they cannot make bulls; and assuredly their mistakes will not, in the opinion of any person of common sense or candour, derogate from their reputation.