Very little is known of this Mr. Jordan, except that his invention pleased greatly, and was found of such practical use, that not only were all new organs in England (virtually from this date) furnished with swells, but himself and son found much occupation in adapting and adding their invention to the older London organs. The lack of a swell is the weakest point of the great majority of German organs. Even Dr. Burney, fifty years after swells had become common in England, expresses, in his famous work entitled _The Present State of Music in Germany, the Netherlands and United Provinces_, two volumes, also _The Present State of Music in France and Italy_, his great surprise to find them utterly unknown upon the Continent. His remarks would hold true at the present day with but little modification, as far as Germany is concerned, few instruments outside the larger ones of recent date possessing this great improvement. The reason of this is to be found, partly in the extremely conservative character of their organ-builders, almost a national trait, and still more in the fact that but little use would be found for a swell organ outside solo playing. With us, nearly the reverse is true, the swell being most indispensable in accompanying choirs as here constituted. Notwithstanding this neglect of what seems to us an indispensable addition to the instrument, the glory of the invention and perfection of the organ justly belongs to Germany. Modern organ-building requires the most profound study of the laws both of mechanics and acoustics, and the German mind was constitutionally fitted, by a natural depth and thoroughness of thought, together with the truly artistic quality of patience, to be successful in solving this great problem,--the creation of the most complex instrument known. France, too, has produced her great organs and organ-builders. If often lacking the sublimity and solidity of tone characteristic of many of the famous German organs, they interest (particularly the American taste) by a greater variety of the so-called "fancy," or solo stops. This difference, too, has grown out of the nature of the duties demanded of the organ and the organist in the service of the Roman Catholic church, and it is these differences of usage which in process of time, combining with further differences of national taste, led to that varied style and treatment which we denominate "Schools of Playing." We divide these schools into the German, French, and English.