Though the basic nature of Howe's patent was recognized, his machine was only a rough beginning. Improvements followed, one after another, until the sewing machine bore little resemblance to Howe's original. John Bachelder introduced the horizontal table upon which to lay the work. Through an opening in the table, tiny spikes in an endless belt projected and pushed the work for ward continuously. Allan B. Wilson devised a rotary hook carrying a bobbin to do the work of the shuttle, and also the small serrated bar which pops up through the table near the needle, moves forward a tiny space, carrying the cloth with it, drops down just below the upper surface of the table, and returns to its starting point, to repeat over and over again this series of motions. This simple device brought its owner a fortune. Isaac M. Singer, destined to be the dominant figure of the industry, patented in 1851 a machine stronger than any of the others and with several valuable features, notably the vertical presser foot held down by a spring; and Singer was the first to adopt the treadle, leaving both hands of the operator free to manage the work. His machine was good, but, rather than its surpassing merits, it was his wonderful business ability that made the name of Singer a household word. By 1856 there were several manufacturers in the field, threatening war on each other. All men were paying tribute to Howe, for his patent was basic, and all could join in fighting him, but there were several other devices almost equally fundamental, and even if Howe's patents had been declared void it is probable that his competitors would have fought quite as fiercely among themselves. At the suggestion of George Gifford, a New York attorney, the leading inventors and manufacturers agreed to pool their inventions and to establish a fixed license fee for the use of each. This "combination" was composed of Elias Howe, Wheeler and Wilson, Grover and Baker, and I. M. Singer, and dominated the field until after 1877, when the majority of the basic patents expired. The members manufactured sewing machines and sold them in America and Europe. Singer introduced the installment plan of sale, to bring the machine within reach of the poor, and the sewing machine agent, with a machine or two on his wagon, drove through every small town and country district, demonstrating and selling. Meanwhile the price of the machines steadily fell, until it seemed that Singer's slogan, "A machine in every home!" was in a fair way to be realized, had not another development of the sewing machine intervened.