On the outer side of one we feel the pulse at the wrist, the radial artery here lying close to the radius.

The position of the radial artery is described in Experiment 102.

The former kind have for the most part consisted of a circular valve and face, with radial apertures, the valve resembling the outstretched wings of a butterfly, and being made to revolve on its central pivot by connecting links between its outer edges, or by its central spindle.

A.The structure of the feathering wheel will be hereafter described in connection with an account of the oscillating engine; and it will be expedient now to restrict any account of the details to the common radial paddle, as applied to ocean steamers.

A.There are two kinds of paddle wheels in extensive use, the one being the ordinary radial wheel, in which the floats are fixed on arms radiating from the centre; and the other the feathering wheel, in which each float is hung upon a centre, and is so governed by suitable mechanism as to be always kept in nearly the vertical position.

In the radial wheel there is some loss of power from oblique action, whereas in the feathering wheel there is little or no loss from this cause; but in every kind of paddle there is a loss of power from the recession of the water from the float boards, or the slip as it is commonly called; and this loss is the necessary condition of the resistance for the propulsion of the vessel being created in a fluid.

A.In the feathering wheel, where every part of any one immerged float moves forward with the same horizontal velocity, the pressure or resistance may be supposed to be concentrated in the centre of the float; whereas, in the common radial wheel this cannot be the case, for as the outer edge of the float moves more rapidly than the edge nearest the centre of the wheel, the outer part of the float is the most effectual in propulsion.

In the feathering wheel the position of the centre of pressure of the entering and emerging floats is continually changing from the lower edge of the floatwhere it is when the float is entering or leaving the waterto the centre of the float, which is its position when the float is wholly immerged; but in the radial wheel the centre of pressure can never rise so high as the centre of the float.

It follows from this investigation, that, in radial wheels, the greater part of the engine power is distributed among the oblique floats.

570. Q.Is the screw propeller as effectual an instrument of propulsion as the radial or feathering paddle? A.In all cases of deep immersion it appears to be quite as effectual as the radial paddle, indeed, more so; but it is scarcely as effectual as the feathering paddle, with any amount of immersion, and scarcely as effectual as the common paddle in the case of light immersions.

570. Q.Is the screw propeller as effectual an instrument of propulsion as the radial or feathering paddle? A.In all cases of deep immersion it appears to be quite as effectual as the radial paddle, indeed, more so; but it is scarcely as effectual as the feathering paddle, with any amount of immersion, and scarcely as effectual as the common paddle in the case of light immersions.

A.In the case of ocean vessels, it is found that paddle vessels fitted with the ordinary radial wheels, and screw vessels fitted with the ordinary screw, are about equally efficient in calms and in fair or beam winds with light and medium immersions.

At the same time, the curved flange at the rim of the screw prevents the dispersion of the water in a radial direction, and it consequently assumes the form of a column or cylinder of water, projected backward from the ship.

The eccentricity in this wheel is not sufficient to keep the floats in the vertical position, but in the position between the vertical and the radial.

THE FLEXOR PEDIS PERFORANS, OR THE DEEP FLEXOR OF THE PHALANGES.This muscle consists of three easily-divided portions: an ulnar, a humeral, and a radial, and has for points of origin the olecranon process of the ulna, the inner condyloid ridge of the humerus, and the posterior surface of the radius.

THE LARGE METACARPAL, OR COLLATERAL ARTERY OF THE CANNON.This, the larger terminal branch of the posterior radial artery, needs brief mention, for the reason that we shall be afterwards concerned with it in the operation of neurectomy.

In some cases I have found it of advantage to put on a tourniquet below the seat of operation, but this is not always advisable, as it distends the radial artery.

Shortly after we started mist formed about us, waxing and waning in density; a slight southerly breeze sprang up, cumulo-stratus cloud formed overhead with a rather windy appearance (radial E. and W.).

A railgrip, made to act at the curves as well as on the straight portions of the rail by being attached to a radial arm fixed to the under frame, assists the stability of the scaffold where required, but the gauge of the rails is altered to render the scaffold more or less stable according to its height.

Consequently the shrinkage along the rings (tangential) is fully twice as much as toward the centre (radial).

Spruce expands less than oak, the ratio of radial to longitudinal expansion being about six to one.

(For sketches showing radial and tangential cleavage, see Fig.

They will be taken from adjoining pieces chosen so that the results will be comparable for use in determining radial and tangential shrinkage.

One of these specimens will be cut with its width in the radial direction and will be used for the determination of radial shrinkage.

Captain Scott, R.N., employs a solid projectile dressed to fit by machinery; but the surfaces of the lands upon which the shot presses are radial to the bore, so that the rotation of the shot tends, not to split the gun, but simply to rotate it in the opposite direction.