Tuesday October 30, 1894

Discussed with M^r Skinner (from Mess^rs Troughton & Simms) plans for new Astrographic micrometer and for Photographic spectroscope.

William Christie, Astronomer Royal

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RH says..... On another topic, Graham Dolan has kindly send me an image of the Great Equatorial Building's balcony under construction - see entry for 19 October. He tells me that this picture can be dated to the summer of 1898, so it seems that it took some time to do the work. It is always interesting to see in these old images that, although the Observatory was closed to the public, it was still a sight for visitors to Greenwich Park - even if they were chiefly there for the view down to the river that the people on the benches at the right of the picture are enjoying.

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Friday October 19, 1894

M^r Crisp & M^r Loughborough with M^r Awdry discussed the above. Also discussed, with M^r Crisp proposed Magnetic Pavilion in the Park and balcony below 36^ft Dome.

Discussed with M^r Simms plans for new Astrographic micrometer & Photographic spectroscope.

William Christie, Astronomer Royal

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RH says..... The 36-foot dome was the new onion-shaped dome that accommodated the larger 28-inch telescope instead of the Great Equatorial telescope that the building had originally contained. This postcard clearly shows the balcony that Christie discussed today.

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The Magnetic House at this time was still where it had been since the 1840s - in the south part of the Royal Observatory's site, but north of the New Physical Observatory. This area today is covered by the dome of the Peter Harrison Planetarium. Despite Christie performing apparently satisfactory experiments to test the effect of ironwork in the new buildings on the magnetic observations, it had obviously become clear that the would have to be performed away from the main site. The picture below shows the new Magnetic Pavilion, built in 1899, in the area of Greenwich Park that became known as the Christie Enclosure. This area, 350 yards east from the main site, once held several telescope domes, including that of the Yapp 36-inch telescope, as well as the Magnetic Pavilion and Magnetograph House. It was all dismantled and returned to the Park when the Observatory moved to Herstmonceux and the Greenwich site became part of the National Maritime Museum.

Friday October 5, 1894

Saw Gen. Donnelly at S. & A. Department. Also Cap^t. Abney with reference to absorption of glass in ultraviolet part of spectrum. He advised use of Feils’ medium flint for photo. Spectroscope and large prisms adapted to a collimator of 2½ inches aperture.

William Christie, Astronomer Royal

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RH says..... Sir John Fretchville Dykes Donnelly was, as this book suggests, "the very model of a modern Major-General", seeing active army service in the Crimea before focusing the rest of his career on scientific education within the Department of Science and Art at South Kensington. Through this he supervised science teaching not only in schools throughout the country, but also within many important higher education institutions. He had been educated at the Royal Military Academy at Woolwich, when Christie's father Samuel Hunter Christie was professor of mathematics.

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The other meeting was with the equally wonderfully-named Sir William de Wiveleslie Abney (1843-1920), a chemist, astronomer and photographer who was a fellow and president of the Royal Astronomical Society. See his obituary here. He had first come to astronomy, at to Greenwich, through his involvement in supervising the photography associated with the 1874 transit of Venus expeditions.

Thursday September 27, 1894

Cleaned outside surface of 28ⁱⁿ O.G. Adjustment of spectroscope in the evening.

William Christie, Astronomer Royal

Monday September 24, 1894

Went to Troughton & Simms with M^r Dyson and arranged with M^r Simms for a new Astrographic micrometer for measuring two plates at same time and for a Photographic spectroscope. Also gave M^r Simms a paper for positions of stops in new altazimuth to give a series of adopted azimuths.

William Christie, Astronomer Royal

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Went with the Astronomer Royal to Troughton & Simms’ works. M^r Simms & the Astronomer Royal discussed photographic spectroscope especially the kinds of glass obtainable, & the Micrometer for the Astrographic measures.

Frank Dyson, Chief Assistant

Thursday September 13, 1894

Saw Director of Works at Admiralty & M^r Crisp about new buildings. Received from M^r Simms small reflecting prism for spectroscope on 28ⁱⁿ telescope.

William Christie, Astronomer Royal

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Half-inch prism for spectroscope of 28 Inch arrived from Troughton & Simms.

Frank Dyson, Chief Assistant

Wednesday August 1, 1894

M^r Deslandres & Comte de la Baume Pluvinel came to see the Observatory and M. Deslandres showed some of his photographs of solar chromosphere (faculæ). M. Pluvinel left two positives of the Eclipse of 1893 at Joal.

William Christie, Astronomer Royal

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RH says..... Deslandres and the Comte de la Baume Pluvinel were well-known figures in French astronomy, working on spectroscopy and photography. In previous decades it was felt that there was little place for these novelties in established national observatories such as Greenwich and Paris and alternative sites were set up, including the Solar Physics Observatory in South Kensington (1878) and Meudon Observatory outside Paris (1875). But it's clear that these were areas in which Christie hope to enhance the reputation of Greenwich, as his New Physical Observatory attests.

Monday July 30, 1894

Arranged mounting of reflecting prism for spectroscope on adapter carried by telescope. This work was put in hand by Niblett.

William Christie, Astronomer Royal

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RH says..... The spectroscope used on the 28-inch telescope was designed by Christie, though as we see here it was the indispensable Niblett who undertook the practical work. The spectroscope can be seen in use in the photograph if you click on the link above.

Saturday July 28, 1894

Tried adjustment of Spectroscope on 28ⁱⁿ telescope and altered posⁿ of Spectroscope collimator as the axis of pencil from O.G. was not reflected along coll^r axis.

William Christie, Astronomer Royal

Thursday May 10, 1894

M^r Hughes from Director of Stores Depart^t made out his list of Office furniture required for new building South Wing. M^r Simms Jun^r commenced mounting Simms & Cooke Equatorials & Water Telescope in South Wing Basement. Mr McGilicuddy[?] from Doching[?] & Son called about a mistake in no of copies of Astr. Results 1891, the 180 separate copies not having been struck off. I complained to him of the slow rate of printing. Settled [illegible] details of mounting of Spectroscope on 28 inch telescope. Went to meeting of R.S. (Papers on Eclipse of 1893 April 16) & to dinner of R.S. Club.

William Christie, Astronomer Royal

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RH says..... E.Walter Maunder had this to say about the Water Telescope:

"An ingenious telescope was set up by Sir George Airy in order to ascertain if the speed of light were different when passing through water than when passing through air. Or, in other words, if the aberration of light would give the same value as at present if we observed through water. The water telescope, as it was called, is kept on the ground floor of the central octagon of the new observatory. The observations obtained with it were hardly quite satisfactory, but gave on the whole a negative result."

The Royal Society Club was a dining club, for the inner circles of the Royal Society. See Archibald Geikie's 1917 Annals of the Royal Society Club; the record of a London dining-club in the eighteenth & nineteenth centuries for background.

Thursday May 3, 1894

Arranged with Desforges (from Troughton & Simms) mounting of Half prism spectroscope on Great Equatorial (28ⁱⁿ). Meeting of Board A of Gov^t Grant Com^ee at R.S. at 3.

William Christie, Astronomer Royal
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RH says..... The Government Grant Committee of the Royal Society, as the name suggests, met to decide how to distribute the sum that the government voted annually for the direct support of scientific research. This scheme dated back to 1850, although only became an annual payment in 1856. Subcommittees were formed for the various branches of science - astronomy and mathematics, as at the British Association for the Advancement of Science, was section A.

Tuesday May 1, 1894

Went to Troughton & Simms in the afternoon about new Altazimuth (in progress), glass diaphragm with scales at right angles for measure of star photo’s, mounting of spectroscope on Great Equatorial &c. M^r Simms showed me an alloy of platinum (2 parts) & copper (1 part) recommended by Johnson & Matthey as uncorrodible, which he proposed to use for the circle of the new Altazimuth.

William Christie, Astronomer Royal

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RH says..... Christie here refers to the Great Equatorial, which is the name normally associated with the 12.8-inch Merz, installed when George Airy was Astronomer Royal. The 28-inch had replaced this in the ROG's Great Equatorial Building, and Christie evidently transferred the name. Johnson and Matthey, a company that still exists, was a precious metals assayer that had produced the standard weights and measures for the International Metric Commission.

The 28-inch telescope had a half-prism spectroscope, designed by Christie himself, that had to be mounted underneath the telescope - a much larger instrument than the one that the building and mount had originally supported. According to the obituary of Christie by Turner, this half-prism design was pioneering, but the "soundness of its principles has since been questioned".