AT the second Congress of Mechanised Farming held at Rhodes House, Oxford, on January 5-8, when recent developments were described, a paper by Mr. E. J. Roberts on “A Year's Progress in Grass Drying” excited much interest. A resume of this paper is published in Engineering of February 5. The author points out that whereas there were only six driers in operation in 1935, there were 46 by the end of the 1936 season. The engineering difficulties in connexion with drying plant have been successfully overcome. This is confirmed by papers at the Congress giving the experience of users. We know that inventors are busy developing new methods and rapid progress in this direction will doubtless soon be made. For the year just closed it is expected that the production will be 10,000 tons. In the United States for the same period, it was 50,000 tons. In countries abroad the usual practice is to dry the grass in large centralized units. In Great Britain, in general, only small localized units are used. This is a pity as it is not the most economical method. In a paper read at the conference by Prof. J. A. Scott Watson, it was shown that the remaining problems are to bring down the cost of the drying plant, the fuel cost and the labour cost and to increase the output. Mr. Roberts in his paper stated that one large drier. evaporated 9 cwt. of water with 1 cwt. of coal for a short period and worked at a normal figure of 8 cwt. Smaller driers give efficiencies of 3J-5J cwt. of water per cwt. of coke. If we take the calorific value of the coal to be 14,000 B.Th.U. and that of the coke to be 13,000 B.Th.U., the advantage lies greatly in favour of the large drier.