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. ALS signed “G. Greenhill,” one page, 8 x 12.5, January 21, 1913. Handwritten letter to Mrs. Silberstein, in full: "I received your kind invitation this morning, and I am sorry to say I shall not have time to alter the arrangements I had made for tomorrow, so as to be able to accept it. I have received Dr. Silberstein's new memoir on Relativity from the Philosophical Magazine. I am very grateful to him for introducing us so agreeably to the subject in his lectures, as I feared I should never be able to make the start required. I was away from London for some time. I hope Dr. Silberstein did not make his promised visit in my absence." In very good to fine condition, with edge splits to folds and a few light stains.
In 1913, Ludwik Silberstein published his 'Second Memoir on Quaternionic Relativity' in the London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science.
From the collection of physicist Ludwik Siberstein.