A little to the south-west of Muirhouse, we pass Drylaw, a place that once belonged to a younger branch of the Foresters of Corstorphine, and then come to the village of Davidson's Mains, or Muttonhole, hole, as it used to be called. The east gate of Barnton faces us, but we shall describe that place later, and, turning to the right along the park wall, we soon see the towers of Lauriston rising between us and the sea. The castle appears to have been built about the end of the 16th century, as over two of the windows we can still see the letters S. A. N. and D. E. M. They are the initials of Sir Archibald Napier and his second wife, Dame Elizabeth Mowbray. They acquired Lauriston from the Foresters in the latter half of the sixteenth century. One of the windows near the roof has a kind of stone shelf at its base, intended to hold a beacon, which could be seen simultaneously from the castles of Merchiston and Barnbougle, the former homes of its master and mistress. At Sir Archibald's death in 1608, Lauriston passed to his younger son, Sir Alexander. He has left a trace of his tenure in the _Celestial Theme_, which is cut on a stone nineteen inches square, and is still preserved here. It was probably calculated for him by his more celebrated brother, John Napier, the inventor of Logarithms, who was deeply versed in astrology. After his death, Lauriston passed away from the Napiers, and in 1683 came into the hands of the family with which its name is most closely associated. John Law, the great financier, succeeded his father here in 1688.[63] [63] See Wood's _Account of the Parish of Cramond_, 1794.