Meanwhile, the progress made in lighting other important points of the Scottish coast had been considerable. The lighthouse at Grass Island in Harris was completed on the 10th of October 1789. On the same date was kindled a light at North Ronaldshay, in Orkney. In 1790, on the 1st of October, a light was exhibited at Pladda, a small island south-west of Arran, in the Firth of Clyde. As a guide to the Pentland Firth a lighthouse was erected on the Pentland Skerries in 1794. The Skerries are a couple of desolate islands, exposed to the stress of the North Sea and the currents of the Pentland Firth; and the works here consist of an upper and lower lighthouse, respectively 100 and 80 feet above the sea-level, and 60 feet apart. They deserve our special notice as the first memorials of the skill and energy of Robert Stevenson as an engineer. He was on the spot when the two lights were first exhibited, October 1, 1794; and, his task completed, sailed from Orkney on the 9th of October in the sloop _Elizabeth_. On the following day he landed within a few miles of Kinnaird Head lighthouse, and continued his journey to Edinburgh by road, reaching the capital in safety. A different fate, however, awaited his former companions; the sloop having put back to Cromarty Roads, was afterwards driven to Orkney, and ultimately lost, when all on board perished.[31] [31] Robert Stevenson, “Account of the Bell Rock Lighthouse,” p. 17 (Edit. 1824). * * * * * We have spoken of a lighthouse erected on North Ronaldshay in 1789. An experience of twelve years showed that its position had been unfortunately selected, and that it by no means assisted the mariner in navigating the difficult straits of the Orkney archipelago. Every winter ships were cast away, and precious lives were lost, on the islands of Stronsay and Sanday, though the latter is only eight miles distant from North Ronaldshay. In 1796 three homeward-bound vessels were lost on this fatal island, and eight more in the next three years. It was therefore resolved, in 1801, that a beacon, or tower of masonry, should be erected upon the Start Point, or eastern extremity of the low shores of the island of Sanday; and erected in such a manner that, if found necessary, it might be converted into a lighthouse.