One O’Clock Gun

 History of Astronomy  No Responses »
Jun 222019
 

Castlehill, Edinburgh, EH1 2NG

The One O'Clock Gun positioned in the Half Moon Battery within the walls of Edinburgh Castle

One O’Clock Gun (© Roger Cornfoot via Wikimedia Commons)

Because of the poor Scottish weather, the notorious haar (sea fog), and smog, the time ball at the top of Nelson Monument on Calton Hill was rarely visible to the ship navigators in the ports along Leith and Newhaven who needed to accurately adjust their clocks. As such, in 1861, an 18-pound muzzle-loading cannon from the Half Moon Battery at Edinburgh Castle was commissioned into “Time Gun” service. Its present-day successor is still fired every day at precisely 1 o’clock, except for Sundays, Good Friday and Christmas Day. However, as the speed of sound is 343 metres per second (770 mph) and docks were about 2 miles (3km) away, the navigators had to account for about 10.5s delay when they set their clocks. This can be seen on the “Edinburgh Time Map” prepared by the 1 o’clock gun’s proposer, Charles Piazzi Smyth. Interestingly, the gun has also seen an instance of military action, as it was fired on 2 April 1916 at a German Zeppelin conducting an air raid during WWI.

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Black and white illustration of the Half Moon Battery within Edinburgh Castle

Half Moon Battery and firing mechanism in 1861 (Wikimedia Commons)

The time signal delay map designed by Piazzi Smyth

Time signal delay map designed by Piazzi Smyth (© Alastair Bruce)

Photograph of Edinburgh Castle showing the smoke after the One O'Clock Gun was fired

Smoke from the One O’Clock Gun (© Kim Traynor via Wikimedia Commons)

Time Ball on Nelson Monument

 History of Astronomy  No Responses »
Jun 222019
 

32 Calton Hill, Edinburgh, EH7 5AA

The Time Ball at the top of the Nelson Monument

Time Ball on Nelson Monument (© Kim Traynor via Wikimedia Commons)

In 1853, the second Astronomer Royal for Scotland, Charles Piazzi Smyth, secured the installation of a time ball at the top of Nelson Monument. This tower, which looks like an “upturned telescope” and is clearly visible from most of Edinburgh, was designed by the architect Robert Burn and erected in 1815. While an interesting curiosity these days, the time ball used to be vitally important to ships in the port of Leith in adjusting their clocks for navigation, as it was  raised and dropped exactly at 1 o’clock each day, a tradition that continues. The ball, constructed of wood, covered in zinc, and weighing 90 kilograms, as well as the operating mechanism were made by Maudslay, Sons and Field of Lambeth, who also made the time ball mechanism for the Greenwich Observatory. It was installed by James Ritchie and Son (Clockmakers) Ltd, who still maintain it to this day on behalf of Edinburgh’s City Council. (There is an untrue myth that the original ball was much heavier, at 762 kilograms, in part perpetuated by Smyth himself!)

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Nelson Monument – Museums and Galleries Edinburgh

Photograph of the National Monument, Nelson Monument, and City Observatory on Calton Hill in the background

National Monument, Nelson Monument (tall tower) and City Observatory from the North (Wikimedia Commons)

Thomas Henderson’s House

 History of Astronomy  No Responses »
Jun 222019
 

1 Hillside Crescent, Edinburgh, EH7 5DY; marked with a blue plaque

Photograph of 1 Hillside Crescent with the blue plaque commemorating Thomas Henderson above the door to the right

1 Hillside Crescent (with a blue plaque)

Thomas Henderson (1798-1844) became the first Astronomer Royal for Scotland in 1834. He was also appointed Regius Professor of Astronomy at the University of Edinburgh and worked at the nearby Calton Hill Observatory until his death. His scientific achievements include the calculation of the parallax of a fixed star (the angle describing the difference in the position of a star on the night sky as measured six months apart), leading him to be the first person to measure the distance to Alpha Centauri, one of a group of nearest stars to the Sun. Unfortunately, delaying the publication of his results led to German astronomer Friedrich Bessel and Russian astronomer Friedrich Struve receiving credit for first measuring stellar parallaxes. Throughout his time in Edinburgh, he lived at 1 Hillside Crescent and is buried in Greyfriars Kirkyard (very near the memorial in stop number 13 on this tour).

Black and white photograph of Thomas Henderson

Thomas Henderson

Photograph of Thomas Henderson's memorial and grave at Greyfrairs Kirkyard

Thomas Henderson’s memorial/graveside at Greyfriars Kirkyard

Photo credit: Wikimedia Commons

Madelvic Electric Car Factory

 Granton  1 Response »
Jan 152019
 

Waterfront Avenue, Edinburgh EH5 1RS

Photograph of the Madelvic Car Factory from 2019
The Madelvic Car factory as it is today

We have now returned to Madelvic, the legacy of Sir William Peck (1862 – 1925) who was a Scottish astronomer, scientific instrument maker, and a prolific inventor. He was the director of the Edinburgh City Observatory from 1889 until his death in 1925. Peck was elected a Fellow of the Royal Society of Edinburgh and a man with vision: not only did he invent telescopes (one can still be seen in the Stirling Highland Hotel) but he also came up with the idea of an electric car, a most astonishing concept in 1899. This electric car, which he named ‘The Brougham’, was produced in this factory building. It was driven by a three-wheeled tractor-style front axle unit, comprising a motor, batteries and a small central wheel, set behind the axle, which propelled the vehicle. This unit was mounted to the front of a chassis, creating a five-wheeled automobile and could be attached to any horse-drawn carriage. To gain publicity Peck used it to provide public transport between Granton and Leith. For a brief period, the Postmaster General of Edinburgh employed Madelvic to carry the mail between the General Post Office and Leith. The fifth wheel is such an iconic design, Peck had it incorporated into the façade of the office building, Madelvic House, which is now the base of granton:hub.

Sepai photograph of the Brougham model from the Madelvic Motor Carriage Co. Ltd. brochure in 1899
Illustration taken from The Madelvic Motor Carriage Co. Ltd. original brochure, 1899
Sepia photograph of the royal mail delivery between Leith and Graton taken from The Madelvic Motor Carriage Co. Ltd. original brochure, 1899
Illustration taken from The Madelvic Motor Carriage Co. Ltd. original brochure, 1899
Sepia photograph of Sir William Peck
Sir William Peck FRSE FRAS (3 January 1862, Castle Douglas, Kirkcudbrightshire – 7 March 1925, Edinburgh) was a Scottish astronomer and scientific instrument maker and founder of the Madelvic Motor Carriage Company
5th Wheel on the Facade of Madelvic House
5th Wheel on the Facade of Madelvic House

The artwork "Madelvic Car Factory" by Cecile Grey
“Madelvic Car Factory” by Cecile Grey