My recent article about the old navigation buoy on Greenock Esplanade was made possible thanks to information supplied by Norman Macdonald.

The story was accompanied by a photograph of the buoy in 1956, by which time it was out of service, on the front lawn of Little Cumbrae lighthouse and also showed Norman's parents, principal lighthouse keeper Allan Macdonald and his wife Maida.

Gourock reader Craig Osborne has kindly given additional information about the buoy.

He told me the Rosneath Patch buoy was supplied and constructed by Pintach & Co, New Broad Street, London, in 1879. It was an invention of French origin.

The Clyde Lighthouse Trustees agreed to try it out on an experimental basis after its use was rejected by Trinity House, which is the authority for England, Wales, the Channel Islands and Gibraltar.

It was moored over the rock in December of that year. The buoy was regularly towed to Princes Pier to be filled with gas.

Following its success, a vessel called the Torch was constructed to carry gas to the buoy.

In 1881, the Perch Light at Port Glasgow, which was constructed in 1862, was supplied by gas via a pipe after the trust built its works there.

By 1899, there were six other gas buoys on the river between Greenock and Port Glasgow powered by gas manufactured in Port Glasgow.

In 1882, Pintach & Co supplied a gas lightship for marking Garvel Perch to replace the 1865 cast iron tower. This vessel had a capacity enabling it to operate for 40 days.

A clockwork mechanism caused a drum to revolve around the light, thus giving four white flashes per minute.

Gas was supplied to the beacon marking the Gantock Rocks about 1885. This beacon and the one marking Bridges Rocks, near Innellan, were constructed by Alan Stevenson, of the renowned family of lighthouse builders referred to in my original story.

Craig Osborne said it would be appropriate to mention the Cloch lighthouse in this connection.

Although it is inscribed 1796, it was not lit until 15 September 1797. Its architect was John Clarkson.

Kermack & Gall built the tower and Thomas Smith and Robert Stevenson added the lantern.

The Cloch's first keeper was Greenock pilot, Thomas Smith.

The Cumbrae lighthouse was first lit on 22 August 1793, and the Toward lighthouse on 1 November 1812.

While once again acknowledging Norman Macdonald for his information allowing me to write the original article about the Rosneath Patch buoy, I am indebted to Craig Osborne for supplying additional background to the aforementioned navigational aids.