Note 10 — Chapter IV · EXTRACTION OF OBELISK FROM QUARRY.

It will be seen that, if the obelisk lies at too low a level to be rolled downwards to the valley, it can be raised by tilting backwards and forwards by means of levers acting from the north and south trenches alternately, as mentioned in section 21. If the butt were raised even a metre above its present level, it would enormously reduce the quantity of rock to be removed before the obelisk could be rolled out.