Copy letter from Robert William Frederick Harrison to Professor W [William] D [Dobinson] Halliburton FRS, Church Cottage, 17 Marylebone Road, NW 'Dear Prof Halliburton, The enclosed Paper by Dr George Dreyer and Mr William Bay BSc has been communicated for the Proceedings [of the Royal Society], but as its length is estimated at considerably more that is usually accepted for the Proceedings the Secretaries are of opinion that it should be considered as for the Philosophical Transactions [of the Royal Society]. If you concur, and are willing to report on the Paper, will you be good enough to make your report on the accompanying form? If you cannot report by an early date, please let me know.' 31 May 1910