Copy letter from Robert William Frederick Harrison, to The Secretary, The Institution of Mechanical Engineers A vacancy arises on 31 December in the representation of the Institution of Mechanical Engineers on the General Board of the National Physical Laboratory owing to the retirement by seniority of J A Aspinall. Their Council should nominate a representative to fill this vacancy for the ensuing six years. W H Maw ceases to be an additional member of the General Board on 31 December, and it not eligible for reappointment. It is desirable that a nomination reach the Royal Society by no later than 7 December. 8 November 1909