SOCIETY OF ARTS.
The lectures at the Society of Arts on the results of the Great Exhibi- tion have been so well attended, that a second series of them has been commenced. Professor Wilson commenced the new series on Wednesday, bwi with ho .a lecture on the Agricultural Products and Implements of the Exhi- Among the points of interest in the earlier portions of the lecture were, the introduction to commerce of a new preparation of potash, extracted sea-water by a process which British chemists may apply in success- ful rivalry with the French producers on the shores of the Mediterranean, who now enjoy. a monopoly in the supply of an article of increasing value to the agriculturist; and the new prospect of gain opened to the English farmer by the cultivation of rape for the sake of its seed, which
is opening up through the enormously increased consumption of rape- seed oil as an anti-friction agent in the lubrication of machinery. This oil is now displacing all others; and the North-western Railway Company takes 40,000 gallons of it yearly for its engines, &c., at a price well remu- nerating to the farmer.
In the later portions of the lecture, the most interesting parts re- lated to the reaping-machines by which our American cousins so distin- guished themselves. As in the case of the flax-cotton inventbn of M. Claussen, which was anticipated eighty years ago by Lady Moira, the reaping-machines of M'Cormack and Hussey were shown to be reinven- tions, or perhaps reproductions, of inventions brought before the English people long ago, and disused because the class for whose benefit they were exeogitated were not intelligent enough to appreciate and adopt them. At the very beginning of the century reaping-machines were modelled and made of working size for sale, for which prizes of medals and money were given by the Scottish agricultural societies. Professor Wilson read from the Mechanic's Magazine of 1825 or 1826 a description of a machine identical with one of the two American machines ; and in 1839 the Reverend Mr. Bell invented a machine for which he was awarded a prize of fifty guineas, which has done in an admirable manner all the reaping of his brother, an eminent farmer in the Corse of Gowrie, for the last fourteen years : two specimens of it were exported to the United States some years ago, and it is now returned to us, almost identi- cally, as the other of the two successful American machines shown in the Exhibition. Mr. Bell's machine cuts twelve acres a day, at a cost of 3s. 6d. an acre; an enormous saving of time, and a saving of at least a half in money cost, compared with the mode of hand-reaping. Touching on other machines—the chaff-cutting and turnip-cutting ma- chines, and the threshing-machines, Professor Wilson indicated the ad- vance in constructive ability shown by our machine-makers, by a state- ment of this sort. At one of the shows of the Royal Agricultural So- ciety, not very remote in point of time, two threshing-machines were exhibited, of very different construction. In one of them, particular por- tions of the mechanism were so good that they only consumed one- fourth of the power needed to overcome the total friction of the machine ; while the other portion of the mechanism consumed all the remaining three-fourths. In the second machine the qualities of the mechanism were reversed : the same parts whicfs were good in the first machine here gave rise to more than three-fourths of the whole resistance ; while the same parts which were bad in the first were here so good that their friction was almost nominal. Now it was obvious, that if the had parts of the two were combined, a machine would be the result which could not be worked—its own friction could not be overcome ; while if the good parts of the two were united a machine would result which could be worked-with little more than a quarter of the resistance offered in either of the two original machines. Such improvements were actually made, and they appeared in the Great Exhibition.
On the minor subject of butter-churns, some points of interest to an important branch of farming economy were mentioned. An American churn was shown which is excellent in warm weather, as it has the best mechanical apparatus for agitating the cream ; but which is comparatively inefficient in cold weather. On the other hand, a French churn inge- niously supplied the means of giving a summer temperature to the cream in winter-time; but its mechanical apparatus was bad. The improve- ment suggested by the placing of these machines side by side with each other in the Exhibition was the simple combination of the good points of each.
Thus were strikingly exhibited the benefits which the Exhibition has afforded, and still promises to afford, to the products and implements of agriculture.