The accompanying Tables I. and II. contain the readings from May 1888 to December 1899 of the new set of deep rook thermometers erected in June 1879 at the Calton Hill Observatory, to replace the old set which were destroyed in September 1876. The tables are in continuation of, and are similarly arranged to, those published by the Royal Society of Edinburgh in Vol. XXXV. part 3 of the Transactions, along with a paper by the late Prof. Piazzi Smyth. The tables published with Prof. Smyth's paper contain the observations made between October 1879 and April 1888, being the beginning of the series with the new set of thermometers.