Copy letter from Theodore E James, to Major Percy Alexander MacMahon, Fellow of the Royal Society 'Soirée Dear Sir, Dr Foster thinks we should have the abaque exhibit of the French mathematician, and also would like you to extend him an invitation. We enclose a blank card which may be useful when you are writing. If the exhibition is unable to come we leave it to your judgement whether it is desirable to still request the exhibit. The Society in such cases pays any reasonable carriage expenses. Yrs [Yours] truly T E James Clerk'. 15 April 1890