Tag Archives: Robert Omond

The Ben Nevis Observatory

24 Oct

I have always been interested in the history of the Ben Nevis Observatory. I have written about it before but I think this remarkable development deserves further comment.
The observatory was opened on the summit of Ben Nevis (4,406 feet), in October 1893; and enlarged in 1894, but observations (as distinct to the actual Observatory) started in 1881, when a determined meteorologist Clement Wragge climbed Ben Nevis to make recordings. He got to the summit virtually every day between early June and mid October and used pigeons to transport his readings to Fort William where his wife took the low level readings and telegraphed the results to London! Wragge hoped that after his considerable efforts, he would be the first Supervisor when the observatory was built, but he was passed over in favour of the experienced meteorologist, Robert Omond.
William Speirs Bruce applied to join the Observatory in1894, he needed experience in recording detailed meteorological data in relation to his plans to lead an expedition to Antarctica. Initially his appointment was a locum post, but he was appointed to a substantive position on the summit, under the leadership of Robert Omond, in1895. His aim to achieve meteorological experience was achieved; in his year on the summit was given the most rigorous training.
In 1896 a Low Level Observatory was built at Fort William and manned by Robert Mossman, who would become closely associated with Bruce and went on the Scotia expedition as Meteorologist. The recordings from these two levels were synchronised, this was a first in Britain and led to increased understanding of weather conditions in mountainous regions.
Bruce’s duties were onerous. Observations were made, every hour whenever possible, in rapidly changing and often challenging, conditions. In winter, when snow made the station isolated enough even for Bruce, the snowdrifts were sometimes so high that the men had to get to their instruments via snow tunnels, or exit the observatory via the tower. This experience plus the changes in wind and fog, was an excellent training for Antarctic meteorology.
It was found that fog was present on the summit for 80% of the time in November, December and January 1895/6 – it was common for the summit to be capped in fog when surrounding summits were clear (later Bruce was to tell his companions in Antarctica that they did not know what fog was unless they had experienced it on Ben Nevis). Temperature comparisons between the high and low stations showed that the average fall in temperature between Fort William and the Summit was 15.3°F, with a mean annual temperature at the summit of 31.5° F, compared with 46.8°F. at the base station. Annual rainfall at the summit was approximately double that at Fort William.
Distinguished scientists visited the summit to observe its activities. Amongst these was C.T.R.Wilson, a Scottish physicist. One morning Wilson noted that the rays of the sun cast his shadow, enormously magnified and surmounted by a coloured halo, onto the surface of a fog cloud on the opposite mountain top (this phenomenon had been described by Johann Silberschlag in 1780 and was called the Brocken Spectre).
Wilson recognised that this phenomenon was due to supersaturated water droplets, in the form of fog, which fragmented the sun’s rays into its component parts.
In subsequent laboratory experiments he used sealed glass containers of supersaturated water droplets, (which he called the Cloud Chamber), to demonstrate images of the tracks of charged particles released by X-rays and radioactive materials. Different sized particles with different speeds created different trail patterns – for example an alpha particle track is thick and straight, others are wispy.
The Cloud Chamber was the first tool to be able to follow the path of otherwise invisible particles and show the variety of their size and speed. Wilson was awarded the Nobel Prize in 1927 for this work.
Bruce spent a year on Ben Nevis. Sadly recurring shortfalls in funds led to the observatory being closed in 1904, nine years after he had left it.

The cloud chamber is described as follows: a sealed environment containing a supersaturated vapour of water or alcohol. An energetic charged particle (for example, an alpha or beta particle) interacts with the gaseous mixture by knocking electrons off gas molecules via electrostatic forces during collisions, resulting in a trail of ionised gas particles. The resulting ions act as condensation centres, around which a mist-like trail of small droplets form if the gas mixture is at the point of condensation. These droplets are visible as a “cloud” track that persist for several seconds while the droplets fall through the vapour. These tracks have characteristic shapes. For example, an alpha particle track is thick and straight, while an electron track is wispy and shows more evidence of deflections by collisions.
Cloud chambers played a prominent role in the experimental particle physics from the 1920s to the 1950s, until the advent of the bubble chamber. In particular, the discoveries of the positron in 1932 and the muon in 1936, both by Carl Anderson (awarded a Nobel Prize in Physics in 1936), used cloud chambers. Discovery of the kaon by George Rochester and Clifford Charles Butler in 1947, also was made using a cloud chamber as the detector. In each case, cosmic rays were the source of ionising radiation.

caption: Ben Nevis Observatory after Ice storm
(photo facing page 64 N.Rudmose Brown’s’Naturalist at the Poles’)


9 Dec

I read a piece recently about conditions on the top of Ben Nevis, horrible– deep snow, fog.

Just over 100 years ago there was a meteorological station on the summit of Ben Nevis. This was a wonderful, progressive concept. Meteorologists wanted to understand weather systems better in order to be able to improve forecasting. The observatory was opened in 1883, funded mostly by private donors (supposedly including Queen Victoria) and it worked in synchrony with a second station at Fort William which provided a continuous record for comparison with records taken from the summit. Temperature comparisons showed that the average fall in temperature between Fort William and the summit was 8.5°C and that the mean annual temperature was -0.3°C at the summit and 8.4°C at the low level observatory. The Fort William station was manned by the 25-year-old Robert Mossman, who was to be a long-term associate and friend of William Speirs Bruce

Before the summit building was constructed, a local man, Clement Wragge climbed the peak daily to make meteorological observations in the summer of 1881, getting up at 4.30 each morning to do so. His wife made the simultaneous observations at Fort William. Wragge was not appointed as Superintendent when the observatory opened which must have riled him considerably, the unanimous choice for Superintendent was Robert Traill Omond an expert meteorologist. Omond was succeeded by Angus Rankin who had been an assistant to Wragg. Both Omond and Rankin were to be long term associates of Bruce also.

Bruce started his apprenticeship for his ‘Scotia’ adventure when he joined the summit observatory as Rankin’s assistant in 1895. He had studied medicine in Edinburgh without much enthusiasm until he was offered a position as surgeon/ naturalist on a whaling expedition to the Antarctic. This experience convinced him of the benefits of a purely scientific expedition to Antarctica and on his return, he gave up medical studies to become a full-time naturalist. Ben Nevis gave him valuable training in meteorological work in all conditions – it could be dangerous to make observations when there was a southerly wind, the observatory was situated close to the cliffs on the north of Ben Nevis. In winter, snow tunnels had to be made to get to the instruments.

His association with Ben Nevis continued. When he led the ‘Scotia’ expedition to Antarctica he built a meteorology base and a base for magnetic observations on Laurie Island in the South Orkneys. He called the meteorological base Omond House after the first superintendent of Ben Nevis. His friend Robert Mossman (of Fort William) played an important part in both the ‘Scotia’ journey to the South Orkneys and the Laurie Island stations. Bruce was determined his scientific work should continue long term Neither the British Foreign Office not the Admiralty were interested in small South Atlantic islands of no strategic significance, so Bruce arranged (with the acquiescence of the British Authorities) for Argentina to take over the stations. Three Argentine scientists worked on the South Orkney base under the supervision of Robert Mossman (from Fort William). This was a decision that was to have long-term geopolitical consequences unforeseeable in 1904. One of the Argentine scientists acted as postmaster, a position that is reco0gnised internationally as a tool of effective administration. The claim of effective administration continues today.

Sadly the Ben Nevis station closed in 1919 due to lack of funds, but the men working there were to have a long lasting influence