The strike continued, and the manufacturers again called upon Mr. Roberts, but with no better result. A third time they called and appealed to Mr. Sharp, the capitalist of the firm, who promised to use his best endeavours to induce his mechanical partner to take the matter in hand. But Mr. Roberts, notwithstanding his reticence, had been occupied in carefully pondering the subject since Mr. Ashton's first interview with him. The very difficulty of the problem to be solved had tempted him boldly to grapple with it, though he would not hold out the slightest expectation to the cotton-spinners of his being able to help them in their emergency until he saw his way perfectly clear. That time had now come; and when Mr. Sharp introduced the subject, he said he had turned the matter over and thought he could construct the required self-acting machinery. It was arranged that he should proceed with it at once, and after a close study of four months he brought out the machine now so extensively known as the self-acting mule. The invention was patented in 1825, and was perfected by subsequent additions, which were also patented. Like so many other inventions, the idea of the self-acting mule was not new. Thus Mr. William Strutt of Derby, the father of Lord Belper, invented a machine of this sort at an early period; Mr. William Belly, of the New Lanark Mills, invented a second; and various other projectors tried their skill in the same direction; but none of these inventions came into practical use. In such cases it has become generally admitted that the real inventor is not the person who suggests the idea of the invention, but he who first works it out into a practicable process, and so makes it of practical and commercial value. This was accomplished by Mr. Roberts, who, working out the idea after his own independent methods, succeeded in making the first self-acting mule that would really act as such; and he is therefore fairly entitled to be regarded as its inventor. By means of this beautiful contrivance, spindle-carriages; bearing hundreds of spindles, run themselves out and in by means of automatic machinery, at the proper speed, without a hand touching them; the only labour required being that of a few boys and girls to watch them and mend the broken threads when the carriage recedes from the roller beam, and to stop it when the cop is completely formed, as is indicated by the bell of the counter attached to the working gear. Mr. Baines describes the self-acting mule while at work as "drawing out, twisting, and winding up many thousand threads, with unfailing precision and indefatigable patience and strength--a scene as magical to the eye which is not familiarized with it, as the effects have been marvellous in augmenting the wealth and population of the country." [5]