This being discover’d, he finds out those Numbers which produc’d Sounds that were Consonants:  As, that two Strings of the same Substance and Tension, the one being double the Length, of the other, give that Interval which is called Diapason, or an Eighth; the same was also effected from two Strings of the same Length and Size, the one having four times the Tension of the other.  By these Steps, from so mean a Beginning, did this great Man reduce, what was only before Noise, to one of the most delightful Sciences, by marrying it to the Mathematicks; and by that means caused it to be one of the most abstract and demonstrative of Sciences.  Who knows therefore but Motion, whether Decorous or Representative, may not (as it seems highly probable it may) be taken into consideration by some Person capable of reducing it into a regular Science, tho not so demonstrative as that proceeding from Sounds, yet sufficient to entitle it to a Place among the magnify’d Arts.

Now, Mr. SPECTATOR, as you have declared your self Visitor of Dancing-Schools, and this being an Undertaking which more immediately respects them, I think my self indispensably obliged, before I proceed to the Publication of this my Essay, to ask your Advice, and hold it absolutely necessary to have your Approbation; and in order to recommend my Treatise to the Perusal of the Parents of such as learn to dance, as well as to the young Ladies, to whom, as Visitor, you ought to be Guardian.

  I am, SIR,

  Your most humble Servant.

  Salop, March 19, 1711-12.

T.

[Footnote 1:  John Weaver.]

* * * * *

No. 335.  Tuesday, March 25, 1712.  Addison.

  Respicere exemplar vitae morumque jubebo
  Doctum imitatorem, et veras hinc ducere voces.

  Hor.

My Friend Sir ROGER DE COVERLEY, when we last met together at the Club, told me, that he had a great mind to see the new Tragedy [1] with me, assuring me at the same time, that he had not been at a Play these twenty Years.  The last I saw, said Sir ROGER, was the Committee, which I should not have gone to neither, had not I been told before-hand that it was a good Church-of-England Comedy. [2] He then proceeded to enquire of me who this Distrest Mother was; and upon hearing that she was Hectors Widow, he told me that her Husband was a brave Man, and that when he was a Schoolboy he had read his Life at the end of the Dictionary.  My Friend asked me, in the next place, if there would not be some danger in coming home late, in case the Mohocks should be Abroad.  I assure you, says he, I thought I had fallen into their Hands last Night; for I observed two or three lusty black Men that follow’d me half way up Fleet-street, and mended their pace behind me, in proportion as I put on to get away from them.  You must know, continu’d the Knight with a Smile,