Years ago we discovered the exact point, the dead centre of middle age. It occurs when you are too young to take up golf and too old to rush up to the net.
It will take time to get a more settled sense of Thompson’s distinction as a historian and a writer. His work spans too many forms for easy judgement, and its aura can be a temptation to short cuts. But a tension between what might be called his nineteenth and his eighteenth century sensibility was certainly at the creative centre of it.
The centre of gravity of any cone is [the point which divides its axis so that] the portion [adjacent to the vertex is] triple
The centre of gravity of any parallelogram lies on the straight line joining the middle points of opposite sides.
In any triangle the centre of gravity lies on the straight line joining any angle to the middle point of the opposite side.
The centre of gravity of any hemisphere [is on the straight line which] is its axis, and divides the said straight line in such a way that the portion of it adjacent to the surface of the hemisphere has to the remaining portion the ratio which 5 has to 3.
The centre of gravity of a parallelogram is the point of intersection of its diagonals.
The centre of gravity of any cylinder is the point of bisection of the axis.
It follows at once from the last proposition that the centre of gravity of any triangle is at the intersection of the lines drawn from any two angles to the middle points of the opposite sides respectively.
If two equal weights have not the same centre of gravity, the centre of gravity of both taken together is at the middle point of the line joining their centres of gravity.
