The Oxford, Cambridge, and Dublin Messenger of Mathematics, Volume 1Macmillan, 1862 - Mathematica |
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Common terms and phrases
a₁ angular points axes axis b₁ c₁ Cambridge centre of gravity chord circle circumscribing cone conic conicoid constant corresponding curve deduced determinant diameter direction direction-cosines distance dx² eliminate ellipse ellipsoid equal equation equiangular spiral evidently expression force formulæ function Geometry given Hence intersection line at infinity line of curvature mathematical middle points normal P. G. Tait P₁ parabola parallel perpendicular polar plane potency PROP proposition Quaternion radical axis radii radius vector ratio rectangular hyperbola result right angles Sapa sides similar Similarly soluble sphere straight line substitution suppose surface symmetrical relation tangent plane tetrahedron theorem triangle of reference trilinear coordinates values variables whence William Allen Whitworth αλ λ μ λ² μ ν аф
Popular passages
Page 206 - To study the nature of the surface more closely, let us find the locus of the middle points of a system of parallel chords.
Page 16 - For if we consider two particles of matter at a certain distance apart, attracting each other under the power of gravity and free to approach, they will approach ; and when at only half the distance each will have had stored up in it, because of its inertia, a certain amount of mechanical force. This must be due to the force exerted ; and, if the conservation principle be true, must have consumed an equivalent proportion of the cause of attraction; and yet, according to the definition of gravity,...
Page 15 - But from whence can this enormous increase of the power come ? If we say that it is the character of this force, and content ourselves with that as a sufficient answer, then it appears to me, we admit a creation of power, and that to an enormous amount ; yet by a change of condition, so small and simple, as to fail in leading the least instructed mind to think that it can be a sufficient cause : — we should admit a result which would equal the highest act our minds can appreciate of the working...
Page 15 - Assume two particles of matter, A and B, in free space, and a force in each or in both by which they gravitate towards each other, the force being unalterable for an unchanging distance, but varying inversely as the square of the distance when the latter varies.
Page 16 - B attract each other less because of increasing distance, then some other exertion of power either within or without them is proportionately growing up ; and again, that when their distance is diminished, as from 10 to 1, the power of attraction, now increased a hundredfold, has been produced out of some other form of power which has been equivalently reduced.
Page 16 - There is one wonderful condition of matter, perhaps its only true indication, namely inertia; but in relation to the ordinary definition of gravity, it only adds to the difficulty. For if we consider two particles of matter at a certain distance apart, attracting each other under the power of gravity and free to approach, they will approach ; and when at only half the distance each will have had stored up in it, because of its inertia, a certain amount of mechanical force. This must be due to the...
Page 40 - ... straight line DE, ie the poles of PQ and RG with respect to the hyperbola lie on the straight line DE. Therefore F is the pole of DE with respect to the rectangular hyperbola passing P, Q, R, and G; but P, Q, R, and G are the centres of the escribed and inscribed circles of the triangle DEF. Therefore if a rectangular hyperbola be so described that each angular point of a given triangle is the pole, with respect to it, of the opposite side, it will pass through the centres of the inscribed and...
Page 222 - To find the condition that the general equation of the second degree may represent two straight lines.
Page 156 - ... the straight lines joining the middle points of opposite edges of the tetrahedron. The edges of the tetrahedron are the diagonals of opposite faces of the parallelepiped.
Page 210 - Before proceeding to other forms of the equation to the ellipsoid, we may use those already given in solving a few problems. Find the locus of a point when the perpendicular from the centre on its polar plane is of constant length. If...