A New Century of Inventions. James White

from three to four hundred millions of pounds. It may be useful to observe that using this Machine for an opposite purpose, that of gaining speed, extreme rapidity may be caused by a power acting very slowly on the axis A B; only in that case, the difference must be enlarged, and the diameters and numbers of the wheels be calculated on the principles of perfect geering—which is as easy in this Machine as in any other.

OF

       A CRANE,

       Which combines VARIABLE POWERS with speed and safety.

       Table of Contents

      Doctor Gregory (in his Mechanics 2d. volume page 157,) thus introduces the description of this Crane, and the observations with which he tags that description.

      “The several Cranes described in this article, as preferable to the common walking Crane, while they are free from the dangers attending that Machine, lose at the same time one of it’s advantages, that is, they do not avail themselves of that addition to the moving power which the weight of the men employed may furnish: yet this advantage has been long since insured by the mechanists on the continent: who cause the labourers to walk upon an inclined plane, turning upon an axis, after the manner shewn in the figure referred to under the article foot-mill—where we have described a contrivance of that kind, well known in Germany nearly 150 years ago. The same principle has been lately brought into notice (probably without knowing it had been adopted before) by Mr. Whyte, (White) of Chevening in Kent: His Crane is exhibited—fig. 2 and 4, Plate 10, as it was described in the Transactions of the Society for the Encouragement of Arts.”