"Physician heal thyself"!--You ought likewise to do this with those who are working Figures; probably you may think that because the highest Cypherer is only in decimal arithmetic, it is not there fore worth your critical attention to be looking previously into the several Sums. But you are to consider that a sum in the Square-Root, or even in the Single Rule of three direct, is to your Pupils of as great importance, as the most abstruse problem in the Mathematicks to an able artist; & you may lay this down for a Maxim, that they will reckon upon your abilities, according as they find you acquainted & expert in what they themselves are studying. If therefore you have resolution (as I do not question your ability) to carry this plan which I have laid down into execution; you will thereby convince them of the propriety of their Subordination to you, & obedience to your instructions, so that you may lead them, without any resistance, and fix them to the Study of whatever Science you think proper, in which they will rise according to their respective Capacities. I have said that you ought to strive "from the beginning" in fixing this very material article in the minds of your Scholars, Viz a Sense of your authority; for one error of Judgment, or false determination will diminish your Ability with them more than doing forty things with truth would increase your authority--They act in this case as you would do in the company of a number of Strangers--A whole evenings conversation, if it was tolerable good Sense, would perhaps make little or no impression on you; But if through hast[e] in speaking, or inattention, any one should let fall a sentence either remarkably foolish, or grossly wicked, it would be difficult if not impossible to persuade you presently that the author was not either a _thick-Scull_, or a _Villain_!--The education of children requires constant unremitting attention. The meanest qualification you can mention in a useful teacher is _diligence_ And without diligence no possible abilities or qualifications can bring children on either with speed or profit. There must be a Combination of qualifications which must all operate strongly & uniformly. In short, give this said Pedagogizing the softest name you will, it is still a "difficult Task." You will meet with numberless difficulties, in your new imployment, which you never dreamt had yet existence. All these you must endeavour to resist & Subdue. This I have seen compared to a Man swimming against a current of Water. But I am mistaken if you will agree, after having six months practice, that the comparison be strong as the truth: You will add to the figure, I am certain, & throw into the Current sharp fragments of _Ice_, & _Blocks_, which would make swimming not only difficult but dangerous! I am not urging these things to discourage you; they are hints for your direction, which, if you will attend to, tho' at first the practice seem rough &