My boy, please keep it in mind that four years of undergraduate work does not qualify one as a mathematician. It is merely the first stepping stone on the way. You have a great deal of studying yet to do, a great many books yet to read and absorb—books, I may say, written by men older, wiser, and more learned than yourself.
Please don't waste your time with such frivolous nonsense as toying with symbols derived from wine barrels. No good can come out of a wine barrel, my boy.
I hope you will soon find yourself in a position to aid me in some of the calculations on conic sections as I outlined them to you in my letter of the 28th December last.[1] I feel that this is important work and will do a great deal to further your career.
With all best wishes,
Sincerely,
Isaac Barrow
[1] This letter was either lost or returned to Dr. Barrow.—S. H.
5 January 1667
London
Dear Mr. Newton:
Thank you for your tabulations on the seven-pounder. I must say you were very prompt in your work; there was no need to work over the holidays.
Your questions show that you are unacquainted with the difficulties of manufacturing military arms; I am not at all surprised at this, because it takes years of training and practical experience in order to learn how to handle the various problems that come up. It is something that no university or college can teach, nor can it be learned from books; only experience in the field can teach it, and you have had none of that.