The following results of observations made with four of the thermometer screens, devised by Mr Aitken of Darroch, form the commencement of an investigation which has been begun at Granton Marine Station, and which is to be carried on there and at Ben Nevis Observatory during the summer and autumn, with the view of finding a more suitable screen for exposing thermometers for meteorological purposes, and, if possible, of determining the mean correction to be applied to the readings of thermometers exposed in the ordinary Stevenson screens. So far, the work has been entirely of a preliminary character, but some points have been brought to light which are of considerable interest.