CROP-DRYING. Artificial methods of saving crops, with out the risk of drying them in the fields, have long been but the endeavour to dry crops, whether of hay or grain, by arti ficial heat was not seriously attempted in Britain till 1866, when Dyson's apparatus was patented. In 1882 Mr. Martin Sutton offered a £ 1 oo prize for "the most efficient and economical method of drying hay or corn crops artificially either before or after being stacked." In the following years the Royal Agricultural Society conducted a number of trials. Just before the World War Mr. Newman of Pershore, a district famous for intensive farming, produced a "6 inch centrifugal blowing fan, driven by a 2 h.p. petrol engine" and helped to revive hopes in the method.
The subject was studied seriously during the World War ; and in 1919 Mr. Charles Tinker, who farmed near Aberdeen, patented the use of "atmospheric or pre-heated air" by means of a blowing fan and a steam-heated coil of pipes in a central structure, the drying being done in a Dutch barn. This may be called the parent invention. It stimulated many experimenters, including the ex perts of the Ministry of Agriculture. Under the authority of the Institute of Agricultural Engineers, located at Oxford and work ing on behalf of the Ministry, investigations were carried out to test and improve the existing apparatus. They resulted in the manufacture of a machine which was put on the market. It was claimed for it that it "performed the work economically and satisfactorily." Trials were made with a great variety of crops, including peas, barley and hay, all stacked immediately after cutting. Meadow hay, cut early in the morning of June 3o, was stacked between the hours of 8.45 and 2.30 P.M. The blowing began at 2.3o and the hay was dry by Io.3o P.M. The price for transport and fuel (64 gallons for Io2 tons of wet hay) was judged to be Li 12S.
Heated Pipes.—The core of the principle remained much the same as in the older inventions. The crop is stacked round a cone of heated pipes and the hot air is driven by a fan from the centre of the cone outwards. One difference between this appa ratus and Mr. Tinker's was that it was portable. The other was a structure connected with furnaces and boilers all under a Dutch roof. The Ministry's machine was shown in operation at the Royal Agricultural Show at Reading in 1925, but the results did not greatly impress the farmers ; and it was generally considered that the pamphlet (issued in 1926 and called "A Preliminary Investi gation into the artificial drying of crops in stack") rather exag gerated the efficiency of the method approved by the Institute of Agricultural Engineers. In 1922 in the neighbourhood of War rington Colonel Lyon dried crops of barley, oats, and mixed clover and rye grass in a machine built, with certain adaptations, on the lines of Mr. Charles Tinker's. The chief difference was that he used hot water instead of hot air. The material was stacked round a close coil of pipes within a cage, and during the drying this cir cular cage was enclosed by a canvas curtain. The hay or corn was supplied to the cage from the top by an ordinary elevator. Of the excellence of the results there is no question. The hay, though the grass was carried immediately after cutting and some times in rain, was very sweet and singularly unbleached. Some of the barley so dried was accepted by the brewers as of malting quality. Both oats and barley had lost excess of moisture without loss of germination.
The prospect of a steady increase in the practice and principles of crop-drying became manifest towards the end of 1927, when a new system of drying sugar beet was perfected by the Institute of Agricultural Engineers at Oxford, working on behalf of the Ministry of Agriculture. A sugar factory for its exploitation was erected at Eynsham, and notable success was achieved ; but which system will prevail and how widely any system may be made generally available, has yet to be proved. Neither mechani cally nor economically is the sum of experience yet sufficient ; but it is no small advance to have proved that crops can on occasion be efficiently and economically dried by artificial means. How much this might mean to farmers in a wet climate is admirably and precisely argued in the Oxford pamphlet. (W. B. T.)