Ordinary Meeting, 2005 March 30

 

BAA Instrument Number 1

Mr Marriott explained that since taking over the post of Curator of Instruments 14 years previously, he had been striving to recover the large number of items which were lost from the Association's instrument collection – those which had apparently been loaned out to members, but never returned. At a recent count he had recovered 38 of them, but still some frustrating omissions had remained, one particularly notable example being the first item ever to have entered the collection, a 31 mm-square specular metal diffraction grating. It had been presented to the Association in the year of its foundation, 1890, as a gift from John Brashear, a prominent American instrument-maker at John Hopkins University, who, upon touring Europe, had been especially impressed by the amateurs whom he had met in the UK. An inscription engraved upon the grating's surface recorded that it had been engineered on Rowland's famous ruling engine in the workshops of John Hopkins University, famed for its then-unprecedented exactitude.

The speaker reported that it had last been seen in 1952, when it had been loaned out to a member, of whom no trace could now be found. To his excitement, however, he had received an unexpected telephone call in 2004 September, from a member apparently wishing to return it. A subsequent trip to Worthing had proved fruitful: in addition to recovering the grating, which he held up for members to see, he had also received a Stevenson spectroscope for the collection.

Mr Marriott then recounted those members who had used the instrument before its loss, noting that many were notable figures in the annals of the Association. He was surprised that no observations made with the instrument seemed to survive, however. He remarked upon how regrettable it seemed that there were now so few amateurs making spectroscopic observations, given that the equipment was now so readily available, and how active the Association's members had been in such work in its early history, particularly in the early 20th century, when cellulose gratings had first appeared.

Following the applause for Mr Marriott's account, the President congratulated him on his tireless efforts to recover such historic instruments from the Association's past. The meeting was then adjourned until 2:30pm on April 23, at the English Heritage Lecture Theatre.

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Dominic Ford

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