Copy letter from Robert William Frederick Harrison to H F Coward 'We are proposing to instal a ventilating fan in the ventilating turret in the roof here to improve the ventilation in the meeting rooms, of which great complaint has been made for a long time. I do not think that the erection of the fan will entail any structural work calling for your intervention, but there is a detail in which I should be glad of your assistance. It will be necessary to hoist the fan on to the roof by means of a derrick, and as you have at the present time a temporary derrick on the roof in connection with the repair of the chimney shaft, I shall be much obliged if you will allow this (suitability strengthened if necessary) to be used for hoisting the the fan when it is ready.' 21 July 1911