'Nothing amuses more harmlessly than computation'

 Lichfield continues to honour its greatest son. A newly restored statue of Samuel Johnson – a miniature version of the great sculpture that broods over the market place – has been unveiled at the King Edward VI School. At the unveiling ceremony, an officer of the Johnson Society read from a letter Johnson wrote to 'a young girl', in which he encourages her to continue with her study of mathematics – a fitting choice, given the setting. This letter was written to Sophia Thrale, one of Hester Thrale Piozzi's daughters, and was only recently discovered, by chance, among a bundle of forgotten papers tucked away in a cupboard in a Gloucestershire country house. It was sold at auction, and is now where it belongs, in the care of the Samuel Johnson Birthplace Museum. 
Here is the full text of the letter:

Dearest Miss Sophy,

By my absence from home, and for one reason and another I owe a great number of letters, and I assure you that I sit down to write yours first. Why you should think yourself not a favourite I cannot guess, my favour will, I am afraid never be worth much, but be its value more or less, you are never likely to lose it, and less likely if you continue your studies with the sure diligence as you have begun them.

Your proficiency in arythmetick is not only to be commended but admired. Your master does not, I suppose come very often, nor stay very long, yet your advance in the Science of numbers is greater than is commonly made by those who for so many weeks as you have been learning, spend six hours a day in the writing school.

Never think, my sweet, that you have arithmetic enough; when you have exhausted your Master, buy Books. Nothing amuses more harmlessly than computation, and nothing is oftener applicable to real business or speculative enquiries. A thousand stories which the ignorant tell, and believe, die away at once, when the computist takes them in his gripe. I hope you will cultivate in yourself a disposition to numerical enquiries; they will give you entertainment in Solitude by the practice, and reputation in publick by the effort. If you can borrow Wilkins’s Real Character, a folio which the Booksellers can perhaps let you have, you will have a very curious calculation, which you are qualified to consider, to show Noah’s Ark was capable of holding all the known animals of the world, with provision for all the time in which the earth was underwater.

Let me hear from you again. I am, Madam, Your Humble Servant

Sam: Johnson