Before we started contributing to this blog, our team published some of the more interesting finds from the Directors' Correspondence in Kew's staff magazine VISTA. We came across some of these stories recently and thought they were deserving of a wider audience.
This story was originally highlighted by our friend and one-time team member Lindsay Rosener and it describes the unusual phenomenon that one 19th century plant hunter, William Fawcett, encountered during his time as Director of the Public Gardens and Plantations in Jamaica.
In 1887, Fawcett wrote to RBG Kew's Assistant Director Daniel Morris, describing a circular rainbow and Brocken Spectre he observed one afternoon, while walking near Strawberry hill, in Jamaica's Blue Mountains [archive ref: DC 210/126].
The "faintly coloured" circular rainbow he witnessed appeared "on the white mist which was driving up the valley". Fawcett measured the sight using his "pencil held with outstretched arm" and his letter to Morris includes a sketch of his impression of the rainbow, along with notes concerning the colour of its rings, which ranged from "yellowish white" to "reddish".
Fawcett's sketch and notes of the circular rainbow he observed while walking in Jamaica's Blue Mountains [archive ref: DC210/126].
Fawcett writes that while measuring the rainbow, he noticed that his "black shadow was doing the same, & every gesticulation I made, could be distinctly seen against the white mist." The black shadow in question was a 'Brocken Spectre', 'broken bow' or 'mountain spectre'. This is an optical illusion in which the observer's shadow appears magnified upon the surface of the clouds.
Although Fawcett recognized the shadow as his own, he describes how "awe-inspiring" such a vision would be to someone without such understanding and suspects that contemporary portrayals of small brained giants, such as 'Jack and the Giant Killer', may stem from the shadows' unusual proportions: "The head was small, the eyes being of course in the centre of the circle, but the limbs in proportion to their distances, grew large, & the legs were of an immense length."
A beautiful example of a Brocken Spectre and circular rainbow taken from Stob Dubh in the Scottish Highlands. Photograph reproduced with kind permission from Gordon Anderson, GA Highland Walks.
The Brocken Spectre, first described in 1780 by Johann Silberschlag, derives its name from the 'Brocken' peak in the Harz Mountains of Germany. The circular rainbow observed by Fawcett is often seen in conjunction with the Spectre and is referred to as a 'glory'.
As is the case with many strange phenomena, the sighting of a Brocken Spectre was once thought to be a bad omen: possibly because one poor climber was said to have been so startled at the sight of this weird giant in the clouds that he stumbled and fell to his death! Thankfully, Fawcett – a man of Science – was well enough informed not to suffer the same fate.
- Helen -