British mathematician (1847-1927) who served as professor of mathematics at the Royal Military Academy at Woolwich, London, and was one of the world's leading experts on applications of elliptic integrals in electromagnetic theory; he also developed a notable rule of thumb for calculating the optimal twist rate for lead-core bullets. Two ALSs, signed "A. G. Greenhill," totaling six pages on two sets of adjoining sheets, 4.5 x 7, 1900 and 1903, both to "Zalinski." The first, in part: "Your letter of June 6 just arrived, about the Orient and Waltham bicycles. I presume the Waltham Co. is the same as the watch makers, so I shall feel quite safe in their hands, and will choose their machine. If however you have already chosen the Orient machine, I am sure it will be quite as good. Please remember the size and weight to be carried; a machine for a small light person would not fit…June has been remarkable for wet weather, so no time has been lost of the riding season for this year." The second, in part: "You must be following the artillery question now being worked on in the Transvaal; we ought to find them very educating; our generals do not seem to get any further. C. V. Boys gave me a reference to a historical article on Calculating Machines by Edmundson published in the Philosophical Magazine about 20 years ago…There are no end of books on the Slide Rule, but you will find that Blaine is no different to the rest…Send for Practical Mathematics by John Perry…He gives the essentials of the Slide Rule in a couple of pages." In overall fine condition.
