The substructure consists of (a) the piers and end piers or abutments, the former sustaining a vertical load, and the latter having to resist, in addition, the oblique thrust of an arch, the pull of a suspension chain, or the thrust of an embankment; and (b) the foundations below the ground level, which are often difficult and costly parts of the structure, because the position of a'bridge may be fixed by considerations which preclude the selection of a site naturally adapted for carrying a heavy structure.
When the parenchyma is developed symmetrically on each side of the midrib or stalk, the leaf is equal; if otherwise, the leaf is unequal or oblique (fig.
The stock is headed off by an oblique transverse cut as shown at a, a slice is then pared off the side as at b, and on the face of this a tongue or notch is made, the cut being in a downward direction; the scion c is pared off in a similar way by a single clean sharp cut, and this is notched or tongued in the opposite direction as the figure indicates; the two are then fitted together as shown at d, so that the inner bark of each may come in contact at least on one side, and then tied round with damp soft bast as at e; next some grafting clay is taken on the forefinger and pushed down on each side so as to fill out the space between the top of the stock and the graft, and a portion is also rubbed over the ligatures on the side where the graft is placed, a handful of the clay is then taken, flattened out, and rolled closely round the whole point of junction, being finished off to a tapering form both above and below, as shown by the dotted line f.
Are immediately above those in the fixed plate, and let the bellows by which air is forced into the cylinder (air, for simplicity, being supposed to be the fluid employed) be put in action; then the air in its passage will strike the side of each opening in the movable plate in an oblique direction (as shown in fig.
In this the crowns of the molars are more or less shortened, with their cusps either arranged in longitudinal lines, or forming four upper and three lower more or less distinct oblique ridges.
In the early stages of the precipitation the polarization is complete in a perpendicular direction, and incomplete in oblique directions.
Hookes wheels with oblique or helical teeth are in fact screws of many threads, and of large diameters as compared with their lengths.
The generality of treatment is indeed remarkable; he gives as the fundamental property of all the conics the equivalent of the Cartesian equation referred to oblique axes (consisting of a diameter and the tangent at its extremity) obtained by cutting an oblique circular cone in any manner, and the axes appear only as a particular case after he has shown that the property of the conic can be expressed in the same form with reference to any new diameter and the tangent at its extremity.
The polarization in a distinctly oblique direction, however, is not perfect, a feature for which more than one reas9n may be put forward.
To comprehend more exactly the discovery of Apollonius, imagine an oblique cone on a circular base, of which the line joining the vertex to the centre of the base is the axis.