AT GREENWICH OBSERVATORY--1856 TO 1866.
1856
"In the Report to the Visitors there is an interesting account of the
difficulties experienced with the Reflex Zenith Tube in consequence of
the tremors of the quicksilver transmitted through the ground.
Attempts were made to reduce the tremor by supporting the
quicksilver trough on a stage founded at a depth of 10 feet below the
surface, but it was not in the smallest degree diminished, and the
Report states that 'The experience of this investigation justifies me
in believing that no practicable depth of trench prevents the
propagation of tremor when the soil is like that of Greenwich Hill, a
gravel, in all places very hard, and in some, cemented to the
consistency of rock.'--With respect to the regulation of the Post
Office clocks, 'One of the galvanic clocks in the Post Office
Department, Lombard Street, is already placed in connection with the
Royal Observatory, and is regulated at noon every day ... other clocks
at the General Post Office are nearly prepared for the same
regulation, and I expect that the complete system will soon be in
action.'--Under the head of General Remarks a careful summary is given
of the work of the Observatory, and the paragraph concludes as
follows: 'Lastly there are employments which connect the scientific
Observatory with the practical world; the distribution of accurate
time, the improvement of marine time-keepers, the observations and
communications which tend to the advantage of Geography and
Navigation, and the study, in a practical sense, of the modifications
of Magnetism; a careful attention to these is likely to prove useful
to the world, and conducive to the material prosperity of the
Observatory: and these ought not to be banished from our system.'--In
September I prepared the first specification for the building to carry
the S.E. Dome.--In September, learning that Hansen's Lunar Tables were
finished in manuscript, I applied to Lord Clarendon and they were
conveyed to me through the Foreign Office: in October I submitted to
the Admiralty the proposal for printing the Tables, and in November I
learned that the Treasury had assented to the expense.--Lieut.
Daynou's eclipses and occultations for longitudes of points
in South Africa, observed in 1854 and 1855, were calculated
here in this year.--On Feb. 16th I made my first application to Sir
C. Wood (First Lord of the Admiralty) for assistance to C. Piazzi
Smyth to carry out the Teneriffe Experiment: grounding it in part on
the failure of attempts to see the solar prominences. He gave
encouragement, and on Mar. 18th I transmitted Piazzi Smyth's Memorial
to the Admiralty: on May 2nd the Admiralty authorized an expense of
_£500_. I drew up suggestions.--The Sheepshanks Fund: After the death
of my friend Richard Sheepshanks, his sister Miss Anne Sheepshanks
wished to bestow some funds in connection with the University of
Cambridge, Trinity College, and Astronomy, to which his name should be
attached. There must have been some conversation with me, but the
first letter is one from De Morgan in August. In September I had a
conversation with Miss Sheepshanks, and sent her my first draft of a
scheme, to which she assented. On Sept. 30th I wrote to Whewell
(Master of Trinity) who was much trusted by Miss Sheepshanks: he
consented to take part, and made some suggestions. There was further
correspondence, but the business did not get into shape in this
year.--In connection with the Correction of the Compass in Iron Ships:
I discussed the observations made in the voyage of the Royal
Charter. On Feb. 13th I proposed to the Admiralty a system of mounting
the compasses with adjustable magnets, and it was ordered to be tried
in the Trident and Transit.--In February I reported to the Admiralty
that the Deal Time-Ball had been successful, and I proposed time-balls
at Portsmouth, Plymouth, and Sheerness. There was much correspondence
in various directions about Portsmouth and Devonport, and in March I
went to Devonport and specially examined Mount Wise and the Devonport
Column.--I had correspondence with Sir Howard Douglas about the sea
breaking over the unfinished Dover Pier. I have an idea that this
followed evidence given by me to a Harbour Commission, in which I
expressed as a certainty that the sea will not be made to break by a
vertical wall."
Of private history: "I returned from Playford on Jan. 18th.--From
June 16th to August 5th I was, with my son Wilfrid, on an expedition
to South Italy and Sicily: on our return from Sicily, we remained for
three days ill at Marseilles from a touch of malaria.--On Dec. 22nd I
went to Playford.--In acknowledgment of the pleasure which I had
derived from excursions in the Cumberland Passes, I made a foot-bridge
over a troublesome stream on the Pass of the Sty Head."
1857
"In the Report to the Visitors, when on the subject of the Altazimuth,
the following paragraph occurs: 'I alluded in a preceding section to
the cutting away of a very small portion of one of the rays of the
three-armed pier which carries the Altazimuth. The quality of the
brickwork is the best that I have ever seen, and not a single brick
was disturbed beyond those actually removed. Yet the effect was to
give the Altazimuth an inclination of about 23". This inclination
evidently depends on the elasticity of the brickwork.'--With reference
to the new S.E. Equatoreal the Report states that 'The support of the
north or upper end of the polar axis has been received, and is planted
within the walls of the building in a position convenient for raising
it to its ultimate destination. It is one piece of cast-iron, and
weighs nearly 5 tons.'--Small changes as previously mentioned had been
noticed with regard to the Zero of Azimuth of the Transit Circle, and
the Report states that 'In regard to the Azimuth of the Transit
Circle, and the Azimuth of its Collimator, Mr Main has brought
together the results of several years, and the following law appears
to hold. There is a well-marked annual periodical change in the
position of the Transit Circle, the southerly movement of the eastern
pivot having its minimum value in September, and its maximum in March,
the extreme range being about 14 seconds; and there is a similar
change, but of smaller amount, in the position of the Collimator. I
cannot conjecture any cause for these changes, except in the motion of
the ground. There is also a well-marked connection between the state
of level of the axis and the temperature. The eastern pivot always
rises when the temperature rises, the extreme range being about 6
seconds. I cannot offer any explanation of this.'--Under the head of
Extraneous Works the Report states that 'The British Government had
for some years past contributed by pecuniary grants to the preparation
of Prof. Hansen's Lunar Tables. In the last winter they undertook the
entire expense of printing a large impression of the Tables. The
reading of the proof-sheets (a very considerable labour) has been
effected entirely at the Observatory. I may take this opportunity of
stating that the use of these Tables has enabled me, as I think,
incontestably to fix the capture of Larissa to the date B.C. 557, May
19. This identification promises to prove valuable, not merely for its
chronological utility, but also for its accurate determination of an
astronomical epoch, the point eclipsed being exactly known, and the
shadow having been very small.'--In April I gave a lecture to the
Royal Astronomical Society on the methods available through the next
25 years for the determination of the Sun's parallax.--Dr
Livingstone's observations for African longitudes were computed at the
Observatory.--The Admiralty enquire of me about the feasibility of
adopting Piazzi Smyth's construction for steadying telescopes on board
ship: I gave a Report, of mixed character, on the whole
discouraging.--I had correspondence with G.P. Bond and others about
photographing the Stars and Moon.--On Feb. 17th Piazzi Smyth's books,
&c. relating to the Teneriffe Experiment were sent to me: I
recommended that an abridged Report should be sent to the Royal
Society.--Respecting the Sheepshanks Fund: there was correspondence
with Miss Sheepshanks and Whewell, but nothing got into shape this
year: Miss Sheepshanks transferred to me _£10,000_ lying at Overend
and Gurney's.--In November experiments were made for the longitude of
Edinburgh, which failed totally from the bad state of the telegraph
wire between Deptford and the Admiralty.--In June the first suggestion
was made to me by Capt. Washington for time-signals on the Lizard
Point: which in no long time I changed for the Start Point.--The
Admiralty call for estimates for a time-ball at Portsmouth: on
receiving them they decline further proceeding.--I was engaged in
speculations and correspondence about the Atlantic Submarine
Cable.--In the Royal Astronomical Society, I presented Memoirs and
gave lectures on the three great chronological eclipses (Agathocles,
Thales, Larissa)."--On Dec. 5th Airy wrote to the Vice-Chancellor of
the University of Cambridge, objecting to the proposed changes
regarding the Smith's Prizes--a subject in which he took much
interest, and to which he ascribed great importance.--On Apr. 27th I
was in correspondence with G. Herbert of the Trinity House, about
floating beacons.--In July I reported to the Treasury on the Swedish
Calculating Engine (I think on the occasion of Mr Farr, of the
Registrar-General's Office, applying for one).--In November I had
correspondence about the launch of the Great Eastern, and the main
drainage of London."
Of private history: "On Jan. 14th I returned from Playford.--From June
27th to Aug. 5th I was travelling in Scotland with my wife and two
eldest sons, chiefly in the West Highlands. On our return we visited
Mrs Smith (my wife's mother) at Brampton.--On Dec. 26th I went to
Playford."
1858
"In the Minutes of the Visitors it is noted that the new Queen's
Warrant was received. The principal change was the exclusion of the
Astronomer Royal and the other Observatory Officers from the
Board.--In the Report to the Visitors it is stated that 'The Papers of
the Board of Longitude are now finally stitched into books. They will
probably form one of the most curious collections of the results of
scientific enterprise, both normal and abnormal, which exists.'--It
appears that the galvanic communications, external to the Observatory,
had been in a bad state, the four wires to London Bridge having
probably been injured by a thunderstorm in the last autumn, and the
Report states that 'The state of the wires has not enabled us to drop
the Ball at Deal. The feeble current which arrives there has been used
for some months merely as giving a signal, by which an attendant is
guided in dropping the Ball by hand.'--Regarding the new Equatoreal
the Report states that 'For the new South-East Equatoreal, the
object-glass was furnished by Messrs Merz and Son in the summer of
last year, and I made various trials of it in a temporary tube carried
by the temporary mounting which I had provided, and finally I was well
satisfied with it. I cannot yet say that I have certainly divided the
small star of gamma Andromedae; but, for such a test, a combination of
favourable circumstances is required. From what I have seen, I have no
doubt of its proving a first-rate object-glass.'--On March 15th was an
annular eclipse of the Sun, for the observation of which I sent
parties fully equipped to Bedford, Wellingborough, and Market
Harborough. The observations failed totally in consequence of the bad
weather: I myself went to Harrowden near Wellingborough.--Respecting
the Altazimuth, the Report states that with due caution as to the zero
of azimuth 'the results of observation are extremely good, very nearly
equal to those of the meridional instrument; perhaps I might say that
three observations with the Altazimuth are equivalent to two with the
Transit Circle.'--Respecting Meteorological Observations the Report
states that 'The observations of the maximum and minimum thermometers
in the Thames, interrupted at the date of the last Report, have been
resumed, and are most regularly maintained. Regarding the Thames as
the grand climatic agent on London and its neighbourhood, I should
much regret the suppression of these observations.'--After much
trouble the longitude of Edinburgh had been determined: 'the retard of
the current is 0.04s very nearly, and the difference of longitudes 12m
43.05s, subject to personal equations.'--The Report concludes thus:
'With regard to the direction of our labours, I trust that I shall
always be supported by the Visitors in my desire to maintain the
fundamental and meridional system of the Observatory absolutely
intact. This, however, does not impede the extension of our system in
any way whatever, provided that such means are arranged for carrying
out the extension as will render unnecessary the withdrawal of
strength from what are now the engrossing objects of the
Observatory.'--I had much correspondence on Comets, of which Donati's
great Comet was one: the tail of this Comet passed over Arcturus on
October 5th.--Respecting the Sheepshanks Fund: In September I met
Whewell at Leeds, and we settled orally the final plan of the
scheme. On Oct. 27th I saw Messrs Sharp, Miss Sheepshanks's
solicitors, and drew up a Draft of the Deed of Gift. There was much
correspondence, and on Nov. 20th I wrote to the Vice-Chancellor of
Cambridge University. A counter-scheme was proposed by Dr Philpott,
Master of St Catharine's College. By arrangement I attended the
Council of the University on Dec. 3rd, and explained my views, to
which the Council assented. On Dec. 9th the Senate accepted the gift
of Miss Sheepshanks.--I had much correspondence throughout this year,
with the Treasury, Herschel, Sabine, and the Royal Society, about the
continuation of the Magnetic Establishments. The Reductions of the
Magnetic Observations 1848-1857 were commenced in February of this
year, under the direction of Mr Lucas, a computer who had been engaged
on the Lunar Reductions.--In this year I came to a final agreement
with the South Eastern Railway Company about defining the terms of our
connection with them for the passage of Time Signals. I was authorized
by the Admiralty to sign the 'protocol' or Memorandum of Agreement,
and it was signed by the South Eastern Railway Directors.--On
Aug. 28th I made my first proposal to Sir John Packington (First Lord
of the Admiralty) for hourly time signals on the Start Point, and in
September I went to the Start to examine localities, &c. On Dec. 23rd
the Admiralty declined to sanction it.--I presented to the Royal
Society a Paper about drawing a great-circle trace on a Mercator's
chart.--In October I gave a Lecture on Astronomy in the Assembly Room
at Bury.--On Jan. 25th I was busied with my Mathematical Tracts for
republication."--In this year Airy published in the Athenaeum very
careful and critical remarks on the Commissioners' Draft of Statutes
for Trinity College. He was always ready to take action in the
interests of his old College. This Paper procured him the warmest
gratitude from the Fellows of the College.
Of private history: "On Jan. 23rd I returned from Playford. From July
5th to Aug. 6th I was on an expedition in Switzerland with my two
eldest sons. At Paris we visited Le Verrier, and at Geneva we visited
Gautier, De La Rive, and Plantamour. We returned by Brussels.--On
Dec. 23rd I went to Playford."--In this year was erected in Playford
Churchyard a granite obelisk in memory of Thomas Clarkson. It was
built by subscription amongst a few friends of Clarkson's, and the
negociations and arrangements were chiefly carried out by Airy, who
zealously exerted himself in the work which was intended to honour the
memory of his early friend. It gave him much trouble during the years
1856 to 1858.
Here is a letter to the Editor of the Athenaeum on some other Trinity
matters:
_1858, November 22_.
DEAR SIR,
In the Athenaeum of November 20, page 650, column 3, paragraph 4,
there is an account of the erection of the statue of Barrow in Trinity
College Antechapel (Cambridge) conceived in a spirit hostile to the
University, and written in great ignorance of the facts. On the latter
I can give the writer some information.
The Marquis of Lansdowne, who was a Trinity man and whose son was of
Trinity, intimated to the authorities of the College that he was
desirous of placing in the antechapel a statue of _Milton_. This,
regard being had to the customs and the college-feelings of Cambridge,
was totally impossible. The antechapel of every college is sacredly
reserved for memorials of the men of that college only; and Milton was
of Christ's College. The Marquis of Lansdowne, on hearing this
objection, left the choice of the person to be commemorated, to
certain persons of the college, one of whom (a literary character of
the highest eminence and a profound admirer of Milton) has not resided
in Cambridge for many years. Several names were carefully considered,
and particularly one (not mentioned by your correspondent) of very
great literary celebrity, but in whose writings there is ingrained so
much of ribaldry and licentiousness that he was at length given
up. Finally the choice rested on Barrow, not as comparable to Milton,
but as a person of reputation in his day and as the best who could be
found under all the circumstances.
Cromwell never was mentioned; he was a member of Sidney College:
moreover it would have been very wrong to select the exponent of an
extreme political party. But Cromwell has I believe many admirers in
Cambridge, to which list I attach myself.
I had no part in the negociations above mentioned, but I saw the
original letters, and I answer for the perfect correctness of what I
have stated. But as I am not a principal, I decline to appear in
public.
It is much to be desired, both for the Athenaeum and for the public,
that such an erroneous statement should not remain uncorrected. And I
would suggest that a correction by the Editor would be just and
graceful, and would tend to support the Athenaeum in that high
position which it has usually maintained.
I am, dear Sir,
Yours very faithfully,
G.B. AIRY.
_Hepworth Dixon, Esq._
1859
"The Report to the Visitors states that 'The Lunar Reductions with
amended elements (especially parallax) for correction of Observations
from 1831 to 1851 are now completed. It is, I think, matter of
congratulation to the Observatory and to Astronomy, that there are now
exhibited the results of uninterrupted Lunar Observations extending
through more than a century, made at the same place, reduced under the
same superintendence and on the same general principles, and compared
throughout with the same theoretical Tables.'--After reference to the
great value of the Greenwich Lunar Observations to Prof. Hansen in
constructing his Tables, and to the liberality of the British
Government in their grants to Hansen, the Report continues thus: 'A
strict comparison of Hansen's Tables with the Greenwich Observations
of late years, both meridional and extra-meridional, was commenced.
The same observations had, in the daily routine of the Observatory,
been compared with the Nautical Almanac or Burckhardt's Tables. The
result for one year only (1852) has yet reached me, but it is most
remarkable. The sum of squares of residual errors with Hansen's Tables
is only one-eighth part of that with Burckhardt's Tables. When it is
remembered that in this is included the entire effect of errors and
irregularities of observation, we shall be justified in considering
Hansen's Tables as nearly perfect. So great a step, to the best of my
knowledge, has never been made in numerical physical theory. I have
cited this at length, not only as interesting to the Visitors from the
circumstance that we have on our side contributed to this great
advance, but also because an innovation, peculiar to this Observatory,
has in no small degree aided in giving a decisive character to the
comparison. I have never concealed my opinion that the introduction
and vigorous use of the Altazimuth for observations of the Moon is the
most important addition to the system of the Observatory that has been
made for many years. The largest errors of Burckhardt's Tables were
put in evidence almost always by the Altazimuth Observations, in
portions of the Moon's Orbit which could not be touched by the
meridional instruments; they amounted sometimes to nearly 40" of arc,
and they naturally became the crucial errors for distinction between
Burckhardt's and Hansen's Tables. Those errors are in all cases
corrected with great accuracy by Hansen's Tables.'--The Report
concludes with the following paragraph: 'With the inauguration of the
new Equatoreal will terminate the entire change from the old state of
the Observatory. There is not now a single person employed or
instrument used in the Observatory which was there in Mr Pond's time,
nor a single room in the Observatory which is used as it was used
then. In every step of change, however, except this last, the ancient
and traditional responsibilities of the Observatory have been most
carefully considered: and, in the last, the substitution of a new
instrument was so absolutely necessary, and the importance of
tolerating no instrument except of a high class was so obvious, that
no other course was open to us. I can only trust that, while the use
of the Equatoreal within legitimate limits may enlarge the utility and
the reputation of the Observatory, it may never be permitted to
interfere with that which has always been the staple and standard work
here.'--Concerning the Sheepshanks Fund: There was much correspondence
about settling the Gift till about Feb. 21st. I took part in the first
examination for the Scholarship in October of this year, and took my
place with the Trinity Seniority, as one of their number on this
foundation, for some general business of the Fund.--With respect to
the Correction of the Compass in Iron Ships: I sent Mr Ellis to
Liverpool to see some practice there in the correction of the
Compass. In September I urged Mr Rundell to make a voyage in the Great
Eastern (just floated) for examination of her compasses, and lent him
instruments: very valuable results were obtained. Mr Archibald Smith
had edited Scoresby's Voyage in the Royal Charter, with an
introduction very offensive to me: I replied fully in the Athenaeum of
Nov. 7th.--The Sale of Gas Act: An Act of Parliament promoted by
private members of the House of Commons had been passed, without the
knowledge or recollection of the Government. It imposed on the
Government various duties about the preparation of Standards.
Suddenly, at the very expiration of the time allowed this
came to the knowledge of Government. On Oct. 1st Lord Monteagle
applied to me for assistance. On Oct. 15th and 22nd I wrote to Mr
Hamilton, Secretary of the Treasury, and received authority to ask for
the assistance of Prof. W.H. Miller.--I made an examination of Mr
Ball's eyes (long-sighted and short-sighted I think).--In February I
made an Analysis of the Cambridge Tripos Examination, which I
communicated to some Cambridge residents." In a letter on this subject
to one of his Cambridge friends Airy gives his opinion as follows: "I
have looked very carefully over the Examination Papers, and think them
on the whole very bad. They are utterly perverted by the insane love
of Problems, and by the foolish importance given to wholly useless
parts of Algebraical Geometry. For the sake of these, every Physical
Subject and every useful application of pure mathematics are cut down
or not mentioned." This led to much discussion at Cambridge. In this
year the Smith's Prizes were awarded to the 4th and 6th Wranglers.
Of private history: "On Apr. 29th Mrs Smith (my wife's mother) died at
Brampton.--From July 4th to Aug. 2nd I was in France (Auvergne and the
Vivarais) with my two eldest sons. Maclear travelled with us to
Paris.--On Dec. 23rd I went to Playford."--Antiquities and historical
questions connected with military movements had a very great
attraction for Airy. On his return from the expedition in France
above-mentioned, he engaged in considerable correspondence with
military authorities regarding points connected with the battle of
Toulouse. And in this year also he had much correspondence with the
Duke of Northumberland concerning his Map of the Roman Wall, and the
military points relating to the same.
1860
"In June Mr Main accepted the office of Radcliffe Observer at Oxford
(Mr Johnson having died) and resigned the First Assistancy at
Greenwich: in October Mr Stone was appointed First Assistant.--At an
adjourned Meeting of the Visitors on June 18th there were very heavy
discussions on Hansen's merits, and about the grant to him. Papers
were read from Sir J. Lubbock, Babbage, South, Whewell, and
me. Finally it was recommended to the Government to grant _£1000_ to
Hansen, which was paid to him.--In the Report to the Board of Visitors
the following remark occurs: 'The apparent existence of a discordance
between the results of Direct Observations and Reflection Observations
(after the application of corrections for flexure, founded upon
observations of the horizontal collimator wires) to an extent far
greater than can be explained by any disturbance of the direction of
gravity on the quicksilver by its distance from the vertical, or by
the attraction of neighbouring masses, perplexes me much.'--With
respect to the discordance of dips of the dipping-needles, which for
years past had been a source of great trouble and puzzle, the Report
states that 'The dipping-needles are still a source of anxiety. The
form which their anomalies appear to take is that of a special or
peculiar value of the dip given by each separate needle. With one of
the 9-inch needles, the result always differs about a quarter of a
degree from that of the others. I can see nothing in its mechanical
construction to explain this.--Reference is made to the spontaneous
currents through the wires of telegraph companies, which are
frequently violent and always occur at the times of magnetic storms,
and the Report continues 'It may be worth considering whether it would
ever be desirable to establish in two directions at right angles to
each other (for instance, along the Brighton Railway and along the
North Kent Railway) wires which would photographically register in the
Royal Observatory the currents that pass in these directions,
exhibiting their indications by photographic curves in close
juxtaposition with the registers of the magnetic elements.'--In
connection with the Reduction of the Greenwich Lunar Observations from
1831 to 1851, the Report states that 'The comparison of Hansen's Lunar
Tables with the Greenwich Observations, which at the last Visitation
had been completed for one year only, has now been finished for the
twelve years 1847 to 1858. The results for the whole period agree
entirely, in their general spirit, with those for the year 1852 cited
in the last Report. The greatest difference between the merits of
Burckhardt's and Hansen's Tables appears in the Meridional Longitudes
1855, when the proportion of the sum of squares of errors is as 31
(Burckhardt) to 2 (Hansen). The nearest approach is in the Altazimuth
Latitudes 1854, when the proportion of the sum of squares of errors is
as 12 (Burckhardt) to 5 (Hansen).'--A special Address to the Members
of the Board of Visitors has reference to the proposals of M. Struve
for (amongst other matters) the improved determination of the
longitude of Valencia, and the galvanic determination of the extreme
Eastern Station of the British triangles.--On Sept. 13th I circulated
amongst the Visitors my Remarks on a Paper entitled 'On the Polar
Distances of the Greenwich Transit-Circle, by A. Marth,' printed in
the Astronomische Nachrichten; the Paper by Mr Marth was an elaborate
attack on the Greenwich methods of observation, and my Remarks were a
detailed refutation of his statements.--On Oct. 20th I made enquiry of
Sabine as to the advantage of keeping up magnetic observations. On
Oct. 22nd he wrote, avoiding my question in some measure, but saying
that our instruments must be changed for such as those at Kew (his
observatory): I replied, generally declining to act on that
advice.--In March and April I was in correspondence with Mr Cowper
(First Commissioner of Works, &c.) about the bells of the Westminster
Clock; also about the smoky chimneys of the various apartments of the
Palace. On Apr. 21st I made my Report on the clock and bells, 20
foolscap pages. I employed a professional musician to examine the
tones of the bells.--In November I was writing my book on Probable
Errors, &c.--I was engaged on the Tides of Kurrachee and Bombay.--The
first examination of Navy telescopes was made for the Admiralty.
--Hoch's Paper on Aberration appeared in the Astronomische
Nachrichten. This (with others) led to the construction of the
water-telescope several years later.--In September I wrote in the
Athenaeum against a notion of Sir H. James on the effect of an
upheaval of a mountain in changing the Earth's axis. In October I had
drawn up a list of days for a possible evagation of the Earth's poles:
but apparently nothing was done upon them.
"In this year I was a good deal occupied for the Lighthouse
Commission. On Feb. 21st Admiral Hamilton (chairman) applied to me for
assistance. In April I went to Chance's Factory in Birmingham on this
business. In May I made my report on the Start Lighthouse, after
inspection with the Commission. In June, with my son Hubert, I visited
the Whitby Lighthouses, and discovered a fault of a singular kind
which most materially diminished their power. This discovery led to a
general examination of lighthouses by the Trinity Board, to a
modification of many, and to a general improvement of system. On June
25th I reported on the Lights at Calais, Cap de Valde, Grisnez, South
Foreland, and North Foreland. In August I had been to the North
Foreland again, and in September to Calais and the Cap d'Ailly. In
October I went with my son Hubert to Aberdeen to see the Girdleness
Lighthouse. On Nov. 10th I made a General Report.
"This was the year of the great total solar eclipse visible in
Spain. At my representation, the Admiralty placed at my command the
large steamship 'Himalaya' to carry about 60 astronomers, British and
Foreign. Some were landed at Santander: I with many at Bilbao. The
Eclipse was fairly well observed: I personally did not do my part
well. The most important were Mr De La Rue's photographic operations.
At Greenwich I had arranged a very careful series of observations with
the Great Equatoreal, which were fully carried out."
The eclipse expedition to Spain, shortly referred to above, was most
interesting, not merely from the importance of the results obtained
(and some of the parties were very fortunate in the weather) but from
the character of the expedition. It was a wonderful combination of
the astronomers of Europe, who were all received on board the
'Himalaya,' and were conveyed together to the coast of Spain. The
polyglot of languages was most remarkable, but the utmost harmony and
enthusiasm prevailed from first to last, and this had much to do with
the general success of the expedition. Those who landed at Bilbao
were received in the kindest and most hospitable manner by Mr
C.B. Vignoles, the engineer-in-chief of the Bilbao and Tudela Railway,
which was then under construction. This gentleman made arrangements
for the conveyance of parties to points in the interior of the country
which were judged suitable for the observation of the eclipse, and
placed all the resources of his staff at the disposal of the
expedition in the most liberal manner. The universal opinion was that
very great difficulty would have been experienced without the active
and generous assistance of Mr Vignoles. It is needless to say that the
vote of thanks to Mr Vignoles, proposed by the Astronomer Royal during
the return voyage, was passed by acclamation and with a very sincere
feeling of gratitude: it was to the effect that 'without the great and
liberal aid of Mr C.B. Vignoles, and the disinterested love of science
evinced by him on this occasion, the success of the "Himalaya" eclipse
expedition could not have been ensured.' There is a graphic and
interesting account of the reception of the party at Bilbao given in
the 'Life of C.B. Vignoles, F.R.S., Soldier and Civil Engineer,' by
O.J. Vignoles, M.A.
Of private history: "On May 26th my venerable friend Arthur Biddell
died. He had been in many respects more than a father to me: I cannot
express how much I owed to him, especially in my youth.--From June
12th to 15th I visited the Whitby Lighthouses with my son
Hubert.--From July 6th to 28th I was in Spain, on the 'Himalaya'
expedition, to observe the total eclipse: I was accompanied by my
wife, my eldest son, and my eldest daughter.--From Oct. 5th to 18th I
went with my son Hubert to Aberdeen to see the Girdleness Lighthouse,
making lateral trips to Cumberland in going and returning.--On
Dec. 21st I went to Playford."
1861
"In the Report to the Visitors there is great complaint of want of
room. 'With increase of computations, we want more room for computers;
with our greatly increased business of Chronometers and
Time-Distribution, we are in want of a nearly separate series of rooms
for the Time-Department: we want rooms for book-stores; and we require
rooms for the photographic operations and the computations of the
Magnetic Department.'--The Report gives a curious history of Dr
Bradley's Observations, which in 1776 had been transferred to the
University of Oxford, and proceeds thus: 'More lately, I applied (in
the first instance through Lord Wrottesley) to the Vice-Chancellor, Dr
Jeune, in reference to the possibility of transferring these
manuscripts to the Royal Observatory.... Finally, a decree for the
transfer of the manuscript observations to the Royal Observatory,
without any condition, was proposed to Convocation on May 2nd, and was
passed unanimously. And on May 7th my Assistant, Mr Dunkin, was sent
to Oxford to receive them. And thus, after a delay of very nearly a
century, the great work of justice is at length completed, and the
great gap in our manuscript observations is at length filled
up.'--With reference to the Transit Circle, it had been remarked that
the Collimators were slightly disturbed by the proximity of the
gas-flames of their illuminators, and after various experiments as to
the cause of it, the Report proceeds thus: 'To my great surprise, I
found that the disturbance was entirely due to the radiation of the
flame upon a very small corner (about 16 square inches) of the large
and massive stone on which the collimator is planted. The tin plates
were subsequently shaped in such a manner as to protect the stone as
well as the metal; and the disturbance has entirely ceased.'
--Regarding the large S.E. Equatoreal, the Report states that
'On the character of its object-glass I am now able to speak, first,
from the examination of Mr Otto Struve, made in a favourable state of
atmosphere; secondly, from the examinations of my Assistants (I have
not myself obtained a sight of a test-object on a night of very good
definition). It appears to be of the highest order. The small star of
gamma Andromedae is so far separated as to shew a broad dark space
between its components. Some blue colour is shewn about the bright
planets.'--It is noted in the Report that 'The Equatoreal observations
of the Solar Eclipse are completely reduced; and the results are
valuable. It appears from them that the error in right ascension of
Burckhardt's Lunar Tables at the time of the eclipse amounted to about
38"; while that of Hansen's (ultimately adopted by Mr Hind for the
calculation of the eclipse) did not exceed 3".'--With regard to
Chronometers it is stated that 'By use of the Chronometer Oven, to
which I have formerly alluded, we have been able to give great
attention to the compensation. I have reason to think that we are
producing a most beneficial effect on the manufacture and adjustment
of chronometers in general.'--With regard to the Cape of Good Hope
Observatory and Survey, the Admiralty enquire of me when the Survey
work will be completed, and I enquire of Maclear 'How is the printing
of your Survey Work?' In 1862 I began to press it strongly, and in
1863 very strongly.--I introduced a method (constantly pursued since
that time at the Royal Observatory) for computing interpolations
without changes of sign.--I had correspondence with Herschel and
Faraday, on the possible effect of the Sun's radiant heat on the sea,
as explaining the curve of diurnal magnetic inequality. (That diurnal
inequality was inferred from the magnetic reductions 1848-1857, which
were terminated in 1860.)--Regarding the proposal of hourly
time-signals on the Start Point, I consulted telegraph engineers upon
the practical points, and on Dec. 21st I proposed a formal scheme, in
complete detail. (The matter has been repeatedly brought before the
Admiralty, but has been uniformly rejected.)--I was engaged on the
question of the bad ocular vision of two or three persons.--The
British Association Meeting was held at Manchester: I was President of
Section A. I gave a Lecture on the Eclipse of 1860 to an enormous
attendance in the Free Trade Hall." The following record of the
Lecture is extracted from Dr E.J. Routh's Obituary Notice of Airy
written for the Proceedings of the Royal Society. "At the meeting of
the British Association at Manchester in 1861, Mr Airy delivered a
Lecture on the Solar Eclipse of 1860 to an assembly of perhaps 3000
persons. The writer remembers the great Free Trade Hall crowded to
excess with an immense audience whose attention and interest,
notwithstanding a weak voice, he was able to retain to the very end of
the lecture....The charm of Professor Airy's lectures lay in the
clearness of his explanations. The subjects also of his lectures were
generally those to which his attention had been turned by other
causes, so that he had much that was new to tell. His manner was
slightly hesitating, and he used frequent repetitions, which perhaps
were necessary from the newness of the ideas. As the lecturer
proceeded, his hearers forgot these imperfections and found their
whole attention rivetted to the subject matter."
Of private history: "On Jan. 2nd there was a most remarkable
crystallization of the ice on the flooded meadows at Playford: the
frost was very severe.--From June 20th to Aug. 1st I was at the Grange
near Keswick (where I hired a house) with my wife and most of my
family.--From Nov. 5th to 14th I was on an expedition in the South of
Scotland with my son Wilfrid: we walked with our knapsacks by the
Roman Road across the Cheviots to Jedburgh.--On Dec. 21st I went to
Playford."
1862
"The Report to the Board of Visitors states that 'A new range of
wooden buildings (the Magnetic Offices) is in progress at the
S.S.E. extremity of the Magnetic Ground. It will include seven
rooms.'--Also 'I took this opportunity (the relaying of the
water-main) of establishing two powerful fire-plugs (one in the Front
Court, and one in the Magnetic Ground); a stock of fire-hose adapted
to the "Brigade-Screw" having been previously secured in the
Observatory.'--'Two wires, intended for the examination of spontaneous
earth-currents, have been carried from the Magnetic Observatory to the
Railway Station in the town of Greenwich. From this point one wire is
to be led to a point in the neighbourhood of Croydon, the other to a
point in the neighbourhood of Dartford. Each wire is to be connected
at its two extremities with the Earth. The angle included between the
general directions of these two lines is nearly a right angle.'--'The
Kew unifilar magnetometer, adapted to the determination of the
horizontal part of terrestrial magnetic force in absolute measure, was
mounted in the summer of 1861; and till 1862 February, occasional
observations (14 in all) were taken simultaneously with the old and
with the new instrument. The comparison of results shewed a steady but
very small difference, not greater probably than may correspond to the
omission of the inverse seventh powers of distance in the theoretical
investigation; proving that the old instrument had been quite
efficient for its purpose.'--Great efforts had been made to deduce a
law from the Diurnal Inequalities in Declination and Horizontal Force,
as shewn by the Magnetic observations; but without success: the Report
states that 'The results are most amazing, for the variation in
magnitude as well as in law. What cosmical change can be indicated by
them is entirely beyond my power of conjecture.'--'I have alluded, in
the two last Reports, to the steps necessary, on the English side, for
completing the great Arc of Parallel from Valencia to the Volga. The
Russian portion of the work is far advanced, and will be finished (it
is understood) in the coming summer. It appeared to me therefore that
the repetition of the measure of astronomical longitude between
Greenwich and Valencia could be no longer delayed. Two Assistants of
the Royal Observatory (Mr Dunkin and Mr Criswick) will at once proceed
to Valencia, for the determination of local time and the management of
galvanic signals.'--'I now ask leave to press the subject of Hourly
Time Signals at the Start Point on the attention of the Board, and to
submit the advantage of their addressing the Board of Admiralty upon
it. The great majority of outward-bound ships pass within sight of the
Start, and, if an hourly signal were exhibited, would have the means
of regulating their chronometers at a most critical part of their
voyage. The plan of the entire system of operations is completely
arranged. The estimated expense of outfit is _£2017_, and the
estimated annual expense is _£326_; both liable to some uncertainty,
but sufficiently exact to shew that the outlay is inconsiderable in
comparison with the advantages which might be expected from it. I know
no direction of the powers of the Observatory which would tend so
energetically to carry out the great object of its establishment,
viz. "the finding out the so much desired Longitude at Sea."'--The
attention of the Visitors is strongly drawn to the pressure on the
strength of the Observatory caused by the observation of the numerous
small planets, and the paragraph concludes thus: 'I shall, however,
again endeavour to effect a partition of this labour with some other
Observatory.'--A small fire having occurred in the Magnetic
Observatory, a new building of zinc, for the operation of
naphthalizing the illuminating gas, is in preparation, external to the
Observatory: and thus one of the possible sources of accidental fire
will be removed.--Miss Sheepshanks added, through me, _£2000_ to her
former gift: I transferred it, I believe, to the Master and Seniors of
Trinity College."--In this year Airy contributed to the Royal Society
two Papers, one "On the Magnetic properties of Hot-Rolled and
Cold-Rolled Malleable Iron," the other "On the Strains in the Interior
of Beams." He gave evidence before the Select Committee on Weights and
Measures, and also before the Public Schools Commission.
In the latter part of 1862 a difference arose between Airy and
Major-General Sabine, in consequence of remarks made by the latter at
a meeting of the Committee of Recommendations of the British
Association. These remarks were to the effect "That it is necessary to
maintain the complete system of self-registration of magnetic
phenomena at the Kew Observatory, because no sufficient system of
magnetic record is maintained elsewhere in England"; implying
pointedly that the system at the Royal Observatory of Greenwich was
insufficient. This matter was taken up very warmly by Airy, and after
a short and acrimonious correspondence with Sabine, he issued a
private Address to the Visitors, enclosing copies of the
correspondence with his remarks, and requesting the Board to take the
matter of this attack into their careful consideration. This Address
is dated November 1862, and it was followed by another dated January
1863, which contains a careful reply to the various points of General
Sabine's attack, and concludes with a distinct statement that he (the
Astronomer Royal) can no longer act in confidence with Sabine as a
Member of the Board of Visitors.
Of private history: There were the usual short visits to Playford at
the beginning and end of the year.--From June 28th to Aug. 5th he was
in Scotland (chiefly in the Western Highlands) with his wife and his
sons Hubert and Osmund. In the course of this journey he visited the
Corryvreckan whirlpool near the island of Scarba, and the following
paragraph relating to this expedition is extracted from his journal:
"Landed in Black Mile Bay, island of Luing, at 10.30. Here by previous
arrangement with Mr A. Brown, agent of the steam-boat company, a
4-oared boat was waiting to take us to Scarba and the Corryvreckan. We
were pulled across to the island of Lunga, and rowed along its length,
till we came to the first channel opening from the main sea, which the
sailors called the Little Gulf. Here the sea was rushing inwards in a
manner of which I had no conception. Streams were running with raving
speed, sometimes in opposite directions side by side, with high
broken-headed billows. Where the streams touched were sometimes great
whirls (one not many yards from our boat) that looked as if they would
suck anything down. Sometimes among all this were great smooth parts
of the sea, still in a whirling trouble, which were surrounded by the
mad currents. We seemed entirely powerless among all these."
In the beginning of this year (1862) the Duke of Manchester, in
writing to the Rev. W. Airy, had said, "I wish your brother, the
Astronomer Royal, could be induced to have investigations made as to
whether the aspects of the Planets have any effect on the weather."
This enquiry produced the following reply:
A subject like that of the occult influences of the planets (using the
word occult in no bad sense but simply as meaning not _thoroughly_
traced) can be approached in two ways--either by the à priori
probability of the existence of such influences, or by the à
posteriori evidence of their effects. If the two can be combined, the
subject may be considered as claiming the dignity of a science. Even
if the effects alone are certain, it may be considered that we have a
science of inferior degree, wanting however that definiteness of law
and that general plausibility which can only be given when true
causes, in accordance with antecedent experience in other cases, can
be suggested.
Now in regard to the à priori probability of the existence of
planetary influences, I am far from saying that such a thing is
impossible. The discoveries of modern philosophy have all tended to
shew that there may be many things about us, unknown even to the
scientific world, but which well-followed accidents reveal with the
most positive certainty. It is known that every beam of light is
accompanied by a beam of chemical agency, totally undiscoverable to
the senses of light or warmth, but admitting of separation from the
luminous and warm rays; and producing photogenic effects. We know
that there are disturbances of magnetism going on about us, affecting
whole continents at a time, unknown to men in general, but traceable
with facility and certainty, and which doubtless affect even our
brains and nerves (which are indisputably subject to the influence of
magnetism).
Now in the face of these things I will not undertake to say that there
is any impossibility, or even any want of plausibility in the
supposition that bodies external to the earth may affect us. It may
well be cited in its favour that it is certain that the sun affects
our magnetism (it is doubtful whether it does so _im_mediately, or
mediately by giving different degrees of warmth to different parts of
the earth), and it is believed on inferior evidence that the moon also
affects it. It may therefore seem not impossible or unplausible that
other celestial bodies may affect perhaps others of the powers of
nature about us. But there I must stop. The denial of the
impossibility is no assertion of the truth or probability, and I
absolutely decline to take either side--either that the influences are
real, or that the influences are unreal--till I see evidence of their
effects.
Such evidence it is extremely difficult to extract from ordinary facts
of observation. I have alluded to the sun's daily disturbance of the
magnet as one of the most certain of influences, yet if you were to
observe the magnet for a single day or perhaps for several days, you
might see no evidence of that influence, so completely is it involved
with other disturbances whose causes and laws are totally unknown.
I believe that, in addition to the effects ascribable to Newtonian
gravitation (as general motion of the earth, precession of the
equinoxes, and tides), this magnetic disturbance is the only one yet
established as depending on an external body. Men in general, however,
do not think so. It appears to be a law of the human mind, to love to
trace an effect to a cause, and to be ready to assent to any specious
cause. Thus all practical men of the lower classes, even those whose
pecuniary interests are concerned in it, believe firmly in the
influence of the moon upon the winds and the weather. I believe that
every careful examiner of recorded facts (among whom I place myself as
regards the winds) has come to the conclusion that the influence of
the moon is not discoverable.
I point out these two things (magnetic disturbances and weather) as
tending to shew that notoriety or the assumed consent of practical
men, are of no value. The unnotorious matter may be quite certain, the
notorious matter may have no foundation. Everything must stand on its
own evidence, as completely digested and examined.
Of such evidence the planetary influence has not a particle.
My intended short note has, in the course of writing, grown up into a
discourse of very unreasonable length; and it is possible that a large
portion of it has only increased obscurity. At any rate I can add
nothing, I believe, which can help to explain more fully my views on
this matter.
* * * * *
In this year (1862, June 9th) Airy received the Honorary Degree of
LL.D. in the University of Cambridge. He was nominated by the Duke of
Devonshire, as appears from the following letter:
LISMORE CASTLE, IRELAND,
_April 19th, 1862_.
MY DEAR SIR,
It is proposed according to usage to confer a considerable number of
Honorary Degrees on the occasion of my first visit to Cambridge as
Chancellor of the University.
I hope that you will allow me to include your name in that portion of
the list which I have been invited to draw up.
The ceremony is fixed for the 10th of June.
I am, my dear Sir,
Yours very truly,
DEVONSHIRE.
_The Astronomer Royal_.
* * * * *
Airy's reply was as follows:
ROYAL OBSERVATORY, GREENWICH,
LONDON, S.E.
_1862, April 21_.
MY LORD DUKE,
I am exceedingly gratified by your communication this day received,
conveying a proposal which I doubt not is suggested by your Grace's
recollection of transactions now many years past.
I have always been desirous of maintaining my connection with my
University, and have in various ways interested myself practically in
its concerns. It would give me great pleasure to have the connection
strengthened in the flattering way which you propose.
I had conceived that alumni of the University were not admissible to
honorary degrees; but upon this point the information possessed by
your Grace, as Chancellor of the University, cannot be disputed.
I am, my Lord Duke,
Your Grace's very faithful servant,
G.B. AIRY.
_His Grace
The Duke of Devonshire_.
* * * * *
There were in all 19 Honorary Degrees of Doctor of Laws conferred on
the 9th of June, including men of such eminence as Armstrong, Faraday,
and Fairbairn.
1863
In this year there were several schemes for a Railway through the
lower part of Greenwich Park, the most important being the scheme of
the London, Chatham and Dover Railway Company. In reference to this
scheme the Report to the Visitors states "I may say briefly that I
believe that it would be possible to render such a railway innocuous
to the Observatory; it would however be under restrictions which might
be felt annoying to the authorities of the Railway, but whose
relaxation would almost ensure ruin to the Observatory."--"The
meridional observations of Mars in the Autumn of 1862 have been
compared with those made at the Observatory of Williamstown, near
Melbourne, Australia, and they give for mean solar parallax the value
8.932", exceeding the received value by about 1/24th part. (A value
nearly identical with this 8.93" has also been found by comparing the
Pulkowa and Cape of Good Hope Observations.)"--"The results of the new
Dip-Instrument in 1861 and 1862 appear to give a firm foundation for
speculations on the state and change of the dip. As a general result,
I may state as probable that the value of dip in the middle of 1843
was about 69°1', and in the middle of 1862 about 68°11'. The decrease
of dip appears to be more rapid in the second half of this interval
than in the first; the dip at beginning of 1853 being about
68°44'."--With reference to the re-determination of the longitude of
Valencia, it is stated that "The concluded longitude agrees almost
exactly with that determined by the transmission of chronometers in
1844; and entitles us to believe that the longitudes of Kingstown and
Liverpool, steps in the chronometer conveyance, were determined with
equal accuracy."--"The computations, for inferring the direction and
amount of movement of the Solar System in space from the observed
proper motions of 1167 stars, have been completed. The result is, that
the Sun is moving towards a point, R.A. 264°, N.P.D. 65° (not very
different from Sir W. Herschel's, but depending much in N.P.D. on the
accuracy of Bradley's quadrant observations), and that its annual
motion subtends, at the distance of a star of the first magnitude, the
angle 0.4". But the comparison, of the sum of squares of apparent
proper motions uncorrected, with the sum of squares of apparent proper
motions corrected for motion of Sun, shews so small an advance in the
explanation of the star's apparent movements as to throw great doubt
on the certainty of results; the sum of squares being diminished by
only 1/25th part."--"I had been writing strongly to Maclear on the
delays in publishing both the geodetic work and the Star Catalogue at
the Cape of Good Hope: he resolves to go on with these works. In
December I am still very urgent about the geodesy."
Of private history: There was the usual short visit to Playford at the
beginning and end of the year.--"From June 27th to August 10th I was
travelling in the North and West of Scotland with my wife, my youngest
son Osmund, and my daughter Annot."
* * * * *
In this year the offer of Knighthood (for the third time) was made to
Airy through the Rt Hon. Sir George C. Lewis, Bart. The offer was
accepted on Feb. 12th, 1863, but on the same day a second letter was
written as follows:
_1863, Feb. 12_.
DEAR SIR,
I am extremely ignorant of all matters connected with court
ceremonial, and in reference to the proposed Knighthood would ask
you:--
1. I trust that there is no expense of fees. To persons like myself of
small fortune an honour may sometimes be somewhat dear.
2. My highest social rank is that given by my Academical Degree of
D.C.L. which I hold in the Universities of Oxford and Cambridge. In
regard to costume, would it be proper that I should appear in the
scarlet gown of that degree? or in the ordinary Court Dress?
I am, Dear Sir,
Yours very faithfully,
G.B. AIRY.
_The Right Honourable
Sir George C. Lewis, Bart.,
&c. &c. &c._
To this letter Sir G.C. Lewis replied that the fees would amount to
about _£30_, an intimation which produced the following letter:
ROYAL OBSERVATORY, GREENWICH, S.E.
_1863, Feb. 19th_.
DEAR SIR,
I have to acknowledge your letter of yesterday: and I advert to that
part of it in which it is stated that the Fees on Knighthood amount to
about _£30_.
Twenty-seven years ago the same rank was offered to me by Lord John
Russell and Mr Spring Rice (then Ministers of the Crown), with the
express notice that no fees would be payable. I suppose that the usage
(whatever it be) on which that notice was founded still subsists.
To a person whose annual income little more than suffices to meet the
annual expenses of a very moderate establishment, an unsought honour
may be an incumbrance. It appears, at any rate, opposed to the spirit
of such an honour, that it should be loaded with Court Expenses in its
very creation.
I hope that the principle stated in 1835 may serve as precedent on
this occasion.
I am, dear Sir,
Your very faithful servant,
G.B. AIRY.
_The Right Honourable
Sir G. C. Lewis, Bart.,
&c. &c. &c._
No intimation however was received that the fees would be remitted on
the present occasion, and after consideration the proposed Knighthood
was declined in the following letter:
ROYAL OBSERVATORY, GREENWICH, S.E.
_1863, April 15_.
DEAR SIR,
I have frequently reflected on the proposal made by you of the honour
of Knighthood to myself. I am very grateful to you for the favourable
opinion which you entertain in regard to my supposed claims to notice,
and for the kindness with which you proposed publicly to express
it. But on consideration I am strongly impressed with the feeling that
the conditions attached by established regulation to the conferring of
such an honour would be unacceptable to me, and that the honour itself
would in reality, under the circumstances of my family-establishment
and in my social position, be an incumbrance to me. And finally I have
thought it best most respectfully, and with a full sense of the
kindness of yourself and of the Queen's Government towards me, to ask
that the proposal might be deferred.
There is another direction in which a step might be made, affecting my
personal position in a smaller degree, but not tending to incommode
me, which I would ask leave to submit to your consideration. It is,
the definition of the Rank of the Astronomer Royal. The singular
character of the office removes it from ordinary rules of rank, and
sometimes may produce a disagreeable contest of opinions. The only
offices of similar character corresponding in other conditions to that
of the British Astronomer Royal are those of the Imperial Astronomers
at Pulkowa (St Petersburg) and Paris. In Russia, where every rank is
clearly defined by that of military grade, the Imperial Astronomer has
the rank of Major-General. In France, the definition is less precise,
but the present Imperial Astronomer has been created (as an attachment
of rank to the office) a Senator of the Empire.
I am, dear Sir,
Your very faithful servant,
G.B. AIRY.
_The Rt Hon. Sir George C. Lewis, Bart.,
&c. &c. &c._
Sir G. C. Lewis died before receiving this letter, and the letter was
afterwards forwarded to Lord Palmerston. Some correspondence followed
between Lord Palmerston and Airy on the subject of attaching a
definite rank to the office of Astronomer Royal, as proposed in the
above letter. But the Home Office (for various reasons set forth)
stated that the suggestion could not be complied with, and the whole
subject dropped.
1864
The following remarks are extracted from the Report of the Astronomer
Royal to the Board of Visitors.--"In a very heavy squall which
occurred in the gale of December 2 of last year, the stay of the lofty
iron pillar outside of the Park Rails, which carried our telegraph
wires, gave way, and the pillar and the whole system of wires
fell."--"An important alteration has been made in the Magnetic
Observatory. For several years past, various plans have been under
consideration for preventing large changes of temperature in the room
which contains the magnetic instruments. At length I determined to
excavate a subterraneous room or cellar under the original room. The
work was begun in the last week in January, and in all important
points it is now finished."--"In the late spring, some alarm was
occasioned by the discovery that the Parliamentary Standard of the
Pound Weight had become coated with an extraneous substance produced
by the decomposition of the lining of the case in which it was
preserved. It was decided immediately to compare it with the three
Parliamentary Copies, of which that at the Observatory is one. The
National Standard was found to be entirely uninjured."--"On November
16 of last year, the Transit Instrument narrowly escaped serious
injury from an accident. The plate chain which carries the large
western counterpoise broke. The counterpoise fell upon the pier,
destroying the massive gun-metal wheels of the lifting machinery, but
was prevented from falling further by the iron stay of the gas-burner
flue."--"The Prismatic Spectrum-Apparatus had been completed in
1863. Achromatic object-glasses are placed on both sides of the prism,
so that each pencil of light through the prism consists of parallel
rays; and breadth is given to the spectrum by a cylindrical lens. The
spectral lines are seen straighter than before, and generally it is
believed that their definition is improved."--"For observation of the
small planets, a convention has been made with M. Le Verrier. From
new moon to full moon, all the small planets visible to 13h are
observed at the Royal Observatory of Greenwich. From full moon to new
moon, all are observed at the Imperial Observatory of Paris. The
relief gained in this way is very considerable."--"In determining the
variations in the power of the horizontal-force and vertical-force
magnets depending on temperature, it was found by experiment that this
depended materially on whether the magnet was heated by air or by
water, and 'The result of these experiments (with air) is to give a
coefficient for temperature correction four or five times as great as
that given by the water-heatings,'"--"With regard to the discordances
of the results of observations of dip-needles, experiments had been
made with needles whose breadth was in the plane passing through the
axis of rotation, and it appeared that the means of extreme
discordances were, for an ordinary needle 11' 45", and for a flat
needle 3' 27"," and the Report continues thus: "After this I need not
say that I consider it certain that the small probable errors which
have been attributed to ordinary needles are a pure delusion."--The
Report states that in the various operations connected with the trials
and repairs of chronometers, and the system of time-signals
transmitted to various time-balls and clocks, about one-fourth of the
strength of the Observatory is employed, and it continues thus:
"Viewing the close dependence of Nautical Astronomy upon accurate
knowledge of time, there is perhaps no department of the Observatory
which answers more completely to the original utilitarian intentions
of the Founder of the Royal Observatory."--"With regard to the
proposal of time-signals at the Start Point, it appears that
communications referring to this proposal had passed between the Board
of Admiralty and the Board of Trade, of which the conclusion was, that
the Board of Trade possessed no funds applicable to the defraying of
the expenses attending the execution of the scheme. And the Admiralty
did not at present contemplate the establishment of these time-signals
under their own authority."--Amongst other Papers in this year, Airy's
Paper entitled "First Analysis of 177 Magnetic Storms," &c., was read
before the Royal Society.
Of private history: "There was the usual visit to Playford in the
beginning of the year.--From June 8th to 23rd I made an excursion with
my son Hubert to the Isle of Man, and the Lake District.--From
Sept. 7th to 14th I was on a trip to Cornwall with my two eldest sons,
chiefly in the mining district.--In August of this year my eldest
(surviving) daughter, Hilda, was married to Mr E.J. Routh, Fellow of
St Peter's College, Cambridge, at Greenwich Parish Church. They
afterwards resided at Cambridge."
1865
"Our telegraphic communications of every kind were again destroyed by
a snow-storm and gale of wind which occurred on Jan. 28th, and which
broke down nearly all the posts between the Royal Observatory and the
Greenwich Railway Station.--The Report to the Visitors states that
'The only change of Buildings which I contemplate as at present
required is the erection of a fire-proof Chronometer Room. The
pecuniary value of Chronometers stored in the Observatory is sometimes
perhaps as much as _£8000_.'--The South Eastern and London Chatham and
Dover scheme for a railway through the Park was again brought
forward. There was a meeting of Sir J. Hanmer's Committee at the
Observatory on May 26th. Mr Stone was sent hastily to Dublin to make
observations on Earth-disturbance by railways there. I had been
before the Committee on May 25th. On Sept. 1st I approved of an
amended plan. In reference to this matter the Report states that 'It
is proper to remark that the shake of the Altazimuth felt in the
earthquake of 1863, Oct. 5th, when no such shake was felt with
instruments nearer to the ground (an experience which, as I have heard
on private authority, is supported by observation of artificial
tremors), gives reason to fear that, at distances from a railway which
would sufficiently defend the lower instruments, the loftier
instruments (as the Altazimuth and the Equatoreals) would be sensibly
affected.'--Some of the Magnets had been suspended by steel wires,
instead of silk, of no greater strength than was necessary for safety,
and the Report states that 'Under the pressure of business, the
determination of various constants of adjustment was deferred to the
end of the year. The immediate results of observation, however, began
to excite suspicion; and after a time it was found that, in spite of
the length of the suspending wire (about 8 feet) the
torsion-coefficient was not much less than 1/6. The wires were
promptly dismounted, and silk skeins substituted for them. With these,
the torsion-coefficient is about 1/210.'--The Dip-Instrument, which
had given great trouble by the irregularities of the dip-results, had
been compared with two dip-instruments from Kew Observatory, which
gave very good and accordant results. 'It happened that Mr Simms, by
whom our instruments now in use were prepared, and who had personally
witnessed our former difficulties, was present during some of these
experiments. Our own instrument being placed in his hands (Nov. 10th
to 19th) for another purpose, he spontaneously re-polished the
apparently faultless agate-bearings. To my great astonishment, the
inconsistencies of every kind have nearly or entirely vanished. On
raising and lowering the needles, they return to the same readings,
and the dips with the same needle appear generally consistent.' Some
practical details of the polishing process by which this result had
been secured are then given.--After numerous delays, the apparatus for
the self-registration of Spontaneous Earth Currents was brought into a
working state in the month of March. A description of the arrangement
adopted is given in the Report.--'All Chronometers on trial are rated
every day, by comparison with one of the clocks sympathetic with the
Motor Clock. Every Chronometer, whether on trial or returned from a
chronometer-maker as repaired, is tried at least once in the heat of
the Chronometer-Oven, the temperature being usually limited to 90°
Fahrenheit; and, guided by the results of very long experience, we
have established it as a rule, that every trial in heat be continued
through three weeks.'--'The only employment extraneous to the
Observatory which has occupied any of my time within the last year is
the giving three Lectures on the Magnetism of Iron Ships (at the
request of the Lords of the Committee of Council on Education) in the
Theatre of the South Kensington Museum. The preparations, however,
for these Lectures, to be given in a room ill-adapted to them,
occupied a great deal of my own time, and of the time of an Assistant
of the Observatory.'--'Referring to a matter in which the interests of
Astronomy are deeply concerned, I think it right to report to the
Visitors my late representation to the Government, to the effect that,
in reference to possible observation of the Transit of Venus in 1882,
it will be necessary in no long time to examine the coasts of the
Great Southern Continent.'"
Of private history: "There were the usual visits to Playford at the
beginning and end of the year.--From June 18th to 26th I was on a trip
in Wales with my sons Hubert and Osmund.--From Sept. 6th to Oct. 2nd I
was staying with most of my family at Portinscale near Keswick: we
returned by Barnard Castle, Rokeby, &c."