The velocity of rotation of the micrometer-screw could therefore be varied for stars of different declination by varying the distance from the apex at which the revolving disk presses upon the revolving cone.
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.
High, with a revolving white light visible 18 m.
BINARY SYSTEM, in astronomy, a system composed of two stars revolving around each other under the influence of their mutual attraction.
Cranes may be divided into two main classes - revolving and non-revolving.
In revolving cranes ease of slewing can be greatly increased by the use of a live ring of conical rollers.
There are many other important points of crane construction too numerous to mention here, but it may be said generally that the advent of electricity has tended to increase speeds, and in consequence great attention is paid to all details that reduce friction and wear, such as roller and ball bearings and improved methods of lubrication; and, as in all other quick-running machinery, great stress has to be laid on accuracy of workmanship. The machinery, thus being of a higher class, requires more protection, and cranes that work in the open are now fitted with elaborate crane-houses or cabins, furnished with weather-tight doors and windows, and more care is taken to provide proper platforms, hand-rails and ladders of access, and also guards for the revolving parts of gearing.
4 is a diagram of a fixed hand revolving jib crane, of moderate size, as used in railway goods yards Fixed and similar places.
The revolving part is made with two side frames of cast iron or steel plates, and to these the lifting gear is attached.
Load is suspended from the crane jib; this jib is attached at the lower end to the side frames, and the upper end is supported by tierods, connected to the framework, the whole revolving together.
Besides the motions of lifting and revolving, there is provided a so-called " racking " motion, by which the lifting crab, with the load suspended, can be moved in and out along the j ib without altering the level of the load.
Another type of fixed revolving crane is the foundry or smithy crane (fig.
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 hydraulic lifting cylinders are placed inside the revolving steel mast or post, and the cabin for the driver FIG.
As types of non-revolving cranes, fig.
The principal component parts of a traveller are the main cross girders forming the revolving bridge, the two end carriages on which the bridge rests, the cranes.
18 shows a modern design of crane intended to command the maximum of yard space, and having some of the characteristics both of the Goliath and of the revolving jib crane, and fig.
In the same way the arrangements finally elaborated by Lodge and Muirhead consisted of a direct coupled antenna and nearly closed condenser circuit, and a similar receiving circuit containing as a detector the steel wheel revolving on oily mercury which actuated a siphon recorder writing signals on paper tape.
The surface formed by revolving the catenary about its directrix is named the alysseide.
It is named the antifriction curve, since a pivot and step having the form of the surface generated by revolving the curve about its vertical axis wear away equally (see MECHANICS: Applied).
The abrasion is effected by pressing the glass against the edge of wheels, or disks, of hard material revolving on horizontal spindles.
The mouth of the bottle is ground by a revolving iron cone, or mandrel, fed with sand and water and driven by steam.
19) consists of a revolving table carrying five or six moulds.
The kilns are made with either fixed or revolving retorts.
On the 8th of March about 1 p.m., the "Merrimac," commanded by Commodore Franklin Buchanan (1795-1871), steamed down the Elizabeth accompanied by two one-gun gun-boats, to engage the wooden fleet of the Federals, consisting of the frigate "Congress," 50 guns, and the sloop "Cumberland," 30 guns, both sailing vessels, anchored off Newport News, and 1 For the idea of the low free-board and the revolving turret Ericsson was indebted to Theodore R.
Wheels creak on their axles as the cogs engage one another and the revolving pulleys whirr with the rapidity of their movement, but a neighboring wheel is as quiet and motionless as though it were prepared to remain so for a hundred years; but the moment comes when the lever catches it and obeying the impulse that wheel begins to creak and joins in the common motion the result and aim of which are beyond its ken.