In revolving cranes ease of slewing can be greatly increased by the use of a live ring of conical rollers.
As the small filings produced by friction seek to pass through the interstices between the rapidly revolving spherical particles in the vortex, they are detained and become twisted and channelled in their passage, and when they reach the edge of the inner ocean of solar dust they settle upon it as the froth and foam produced by the agitation of water gathers upon its surface.
With portable cranes means must be provided to ensure the requisite stability against overturning; this is done by weighting the tail of the revolving part with heavy weights, and in steam cranes the FIG.
The dry sugar then passes into a rotating screen fitted with two meshes, so that three grades of sugar are obtained, the coarsest being that which falls out at the lower end of the revolving screen.
The bodies of this class consist of eight major planets moving round the sun at various distances, and of an unknown number of minor planets, much smaller than the major planets, forming a separate group. Thirdly, satellites, or secondary planets revolving around the major planets, and therefore accompanying them in their revolutions around the sun.
