But while the inventors of these schemes may have been honest, there is another class who deliberately set out to perpetrate a fraud. Their machines work, and work well, but there is always some concealed source of power, which causes them to move. As a general rule, such inventors form a company or corporation of unlimited "lie-ability," as De Morgan phrases it, and then they proceed by means of flaring prospectuses and liberal advertising, to gather in the dupes who are attracted by their seductive promises of enormous returns for a very small outlay. Perhaps the most widely known of these fraudulent schemes of recent years was the notorious Keeley motor, the originator of which managed to hoodwink a respectable old lady, and to draw from her enormous supplies of cash. At his death, however, the absolutely fraudulent nature of his contrivances was fully disclosed, and nothing more has been heard of his alleged discovery. But, while he lived and was able to put forward claims based upon some apparent results, he found plenty of fools who accepted the idea that there is nothing impossible to science. It is true that the Keeley motor was examined by several committees and some very respectable gentlemen acted in such a way as to give a seeming endorsement of the scheme, but it must not be supposed for an instant that any well-educated engineers and scientific men were deceived by Mr. Keeley's nonsense. The very fact that he refused to allow a complete examination of his machine by intelligent practical men, ought to have been enough to condemn his scheme, for if he had really made the discovery which he claimed there would have been no difficulty in proving it practically and thoroughly, and then he might have formed company after company that would have rewarded him with "wealth beyond the dreams of avarice." The Keeley motor was not put forward as a perpetual motion; in these days none of these schemes is admitted to be a perpetual motion, for that term has now become exceedingly offensive and would condemn any invention; but the result is the same in the end, and the whole history of perpetual motion is permeated with frauds of this kind, some of them having been so simple that they were obvious to even the most unskilled observer, while others were exceedingly complicated and most ingeniously concealed. Many years ago a number of these fraudulent perpetual-motion machines were manufactured in America and sent over to Great Britain for exhibition, and quite a lucrative business was done by showing them in various towns. But the fraud was soon detected and the British police then made it too warm for these swindlers. Mr. Dircks, in his "Perpetuum Mobile," has given accounts of quite a number of these impostures. The following are some of the most notable: