[PDF] - Figure 1: Go ogle image of Ro y al Observ atory . The PDF Document

SLIDE 1 Figure 1: Go

gle

image

f

Ro y al Observ atory . The H-shap ed main building w as completed in 1828. The R

y

al Obser v a tor y, Cape

f

Good Hope, a V aluable Cul tural Pr

per

ty Prepared b y I.S. Glass South Afric an Astr

nomic

al Observatory, PO Box 9, Observatory 7935, South Afric a isg@saao.ac.za 1 Geographical p

sition

The Ro y al Observ atory , Cap e

f

Go

d

Hop e is the

riginal

name for the headquarters

f

the presen t-da y South African Astronomical Observ atory . It is situated in the suburb

f

Observ atory , a part

f

Cap e T

wn,

W estern Cap e Pro vince, Republic

f

South Africa. The en tire prop ert y

f

9 hectares

ccupies

a small hill 3 km east

f

cen tral Cap e T

wn,

within the Tw

Riv

ers Urban P ark. The lo cation w as c hosen to b e within view

f

the Cit y's harb

ur

to p ermit the visual signalling

f

time to visiting ships. The prop ert y is

ne
f

the last remaining places close to the cit y cen tre where the

riginal

ecology

f

the area is preserv ed. 2 Longitude and Latitude The Observ atory is situated at longitude 01h 13m 54s.6 E; latitude 33

56

03 00 .5 S; elev ation 15m. This is the precise place

ccupied

b y the Airy T ransit Circle, up

n

whic h all South African geographical p

sitions

w ere formerly based. 3 General description and w

rld

cultural imp

rtance

The Ro y al Observ atory , Cap e

f

Go

d

Hop e, w as created

n

20 Octob er 1820 b y an Order

f

King George IV

f

the United Kingdom, a colon y

f

whic h the Cap e then w as. The rst building w as completed in 1828. F

r

most

f

its existence it w as the ma jor con tributor to p

sitional

astronom y in the southern hemisphere. Among its most notew

rth

y ac hiev emen ts are: the rst successful measuremen ts

f

the distance

f

a star (Alpha Cen tauri) b y Thomas Henderson (1832-3) and the rst use

f

photograph y to mak e a systematic sky surv ey (Gill, 1885

n).

Gill w as

ne
f

the leaders

f

the Astrophotographic Congress, the precursor

f

the In ternational Astronomical Union. 1

SLIDE 2 4 P artial in v en tory

f

extan t items 4.1 Buildings

The

main building

f

the Observ atory (see Fig. 1) w as completed in 1828. The cen tral part comprised

bserving

c ham b ers for a transit telescop e and a m ural circle as w ell as an en trance hall and t w

small

computing ro

ms.

The w est wing comprised quarters for the Astronomer and the east for t w

assistan

ts. It w as designed b y the noted na v al arc hitect John Rennie, Chief Engineer to the Admiralt y .

Other

early structures include the south meridian mark for the m ural circle (ca 1828) and a dome running

n

cannon balls dating from 1849 (for the 7-inc h Merz telescop e).

The

18-inc h dome (former heliometer

bserv

atory), 1888.

The

McClean (Victoria) dome

f

1897; an early w

rk

b y the in ternationally famous arc hitect Herb ert Bak er. 4.2 Some mo v able artefacts surviving

A

rep eating transit b y Dollond, describ ed in a publication

f

1820. (used b y the rst astronomer b efore the completion

f

the main building).

7-inc

h telescop e b y Merz (1849). Used for T ransit

f

V en us 1882. Used also b y R T A Innes, the disco v erer

f

Pro xima Cen, for double star w

rk.
A

sp eculum mirror b y W Hersc hel (1811).

Time

signal pistol 1833.

Regulator

clo c ks b y Molyneux, Hardy , Den t and Rieer. The Hardy clo c k, whic h dates from the 1820s

r

sligh tly earlier, w as in the T ransit Ro

m

and w as used b y Henderson in his Alpha Cen w

rk;

the Molyneux clo c ks (one eac h sidereal and mean) date from a similar time.

Ross

lens used b y Gill for his ep

c

h-making photograph y

f

Great Comet

f

1882

Large

Dallmey er p

rtrait

lens used for Cap e Photographic Durc hm usterung { the rst photographic sky surv ey

Ey

epiece and lens

f

Airy T ransit circle (installed 1854).

\Kew

P attern" Heliograph b y Dallmey er (1878).

6-inc

h Grubb telescop e (1882).

Astrographic

telescop e (Grubb, 1889).

McClean

(Victoria) telescop e (Grubb, 1897).

Gill

transit circle (1905), the precursor

f

all mo dern transit circles.

18-inc

h telescop e (1955)

n

Heliometer moun t b y Repsold (1885). In addition, the library , whic h is the National Library

f

Astronom y , is

ne
f

the most comprehensiv e astronomical libraries in the w

rld,

b

th

for an tique and con temp

rary

material. 5 Brief surv ey

f

the history

f

the site and its uses In pre-colonial times the prop ert y w as probably used for grazing b y the indigenous San pastoralists. Later, but b efore it w as acquired for the Observ atory , the area w as farmland, though ro c ky , treeless and windsw ept. It nev ertheless supp

rted

a remark able v ariet y

f

seasonal grasses and bulbs. It is underlaid b y greyw ac k e, quartzitic limestone and shale. Although it is the habitat

f

man y in teresting

ra

and fauna, it is particularly noted for b eing the last remaining natural habitat

f

a rare Iris Mor ae a aristata and the northern limit

f

the W estern Leopard T

ad

Bufo p antherinus, an endangered sp ecies. F rom c a 1820 the prop ert y has b een in use as an

bserv

atory . In 1971, it b ecame part

f

the South African Astronomical Observ atory . No longer barren,

v

er the nearly t w

cen

turies

f

its existence the site has b een plan ted extensiv ely with shrubs and trees to act as windbreaks. 2

SLIDE 3 Figure 2: Photograph

f

Ro y al Observ atory c a. 1842. 6 Authen ticit y and in tegrit y W e are fortunate in ha ving a n um b er

f

photographs

f

the Observ atory dating from 1842 (See Fig. 2). These are the

ldest

photographs tak en in South African and the

ldest
f

an y

bserv

atory an ywhere (excepting JFW Hersc hel's photograph

f

his father's 48-inc h telescop e). Man y

f

the buildings

n

the site are

riginal

structures. The Main Building, commenced in 1825 and completed in 1828, is still extan t and has b een mo died

nly

marginally . Tw

copp

er domes, sho wn in the 1842 photograph, w ere remo v ed in 1883 and the cen tral lan tern structure w as remo v ed in 1961. The Ro y al Observ atory , as a living institution, has ev

lv

ed con tin uously since its foundation. The

riginal

instrumen ts, consisting

f

a transit and a m ural circle, w ere lo cated in the Main Building. By 1855, these had b een replaced b y a transit circle designed b y Airy . In 1849 a 7-inc h Merz telescop e with dome w as added. A magnetic

bserv

atory , comprising sev eral buildings, w as established in 1841 but none

f

these surviv e to da y . Still within the 19th cen tury , a photo-heliograph designed b y de la Rue w as installed in 1876. During the regime

f

Da vid Gill,

ne
f

the greatest astronomers

f

the 19th cen tury , activit y

n

the site reac hed its zenith. Numerous buildings from Gill's time are extan t, including the Astrographic dome (1888), the Heliometer dome (1888), the McClean dome (1895) and the Gill T ransit Circle (1905). The 20th cen tury sa w the New Oces (c a 1920), the WWI I Optical W

rkshop

(no w lecture theatre), the Ly

t

coronagraph (1958) and the T ec hnical Building (c a 1988). Numerous

ther

small buildings ha v e come and gone during this p erio d, including the F ranklin-Adams telescop e (ca 1909), the 40-inc h (Elizab eth) T elescop e (1964) and the Astrolab e Hut (ca 1960s). 7 Cultural and sym b

lic

dimension

f

the site The Ro y al Observ atory w as the rst ma jor scien tic institution to b e erected

n

the con tinen t

f

Africa, so far as is kno wn. F

r

m uc h

f

the 19th cen tury it

ccupied

an imp

rtan

t p

sition

in the Cap e Colonial hierarc h y , His

r

Her Ma jest y's Astronomer b eing called up

n

to giv e advice and to serv e

n

the b

ards
f

cultural and educational institutions. T

the

general public it w as kno wn as the supplier

f

time services,

p

erating a no

nda

y cannon (as it still do es) and time balls at v arious places in the Cap e Colon y . It w as also the rep

sitory
f

standard w eigh ts and measures for the colon y . The w eather records are the longest-running in South Africa. T

da

y it forms the headquarters

f

the South African Astronomical Observ atory , where astronomers ha v e their

ces,

data reductions are carried

ut

and instrumen ts are constructed. The curren t

bserv

ational activities

f

the SAA O are cen tred in Sutherland, ab

ut

400kms in to the in terior. 8 Do cumen tation and Arc hiv es All phases

f

the existence

f

the Ro y al Observ atory are w ell-do cumen ted. Large amoun ts

f

material exist in the follo wing arc hiv es: Hydrographic Oce

f

the Ro y al Na vy (UK), Ro y al Green wic h Observ atory Arc hiv es (no w in Cam bridge Univ ersit y Library), the South African Go v ernmen t Arc hiv es and,

f

course, the SAA O Arc hiv es, k ept

n

the Ro y al Observ atory site. 3

SLIDE 4 9 Presen t site managemen t The prop ert y is

wned

at presen t b y the National Researc h F

undation

(NRF), the um brella agency

f

whic h the SAA O and a n um b er

f
ther

scien tic institutes form part. It is used exclusiv ely for astronomical purp

ses.

Protection: The prop ert y is cen tral to the Tw

Riv

ers Urban P ark, a conserv ation area established b y the Cit y

f

Cap e T

wn.

It is b

rdered

to the East and North b y w etlands. As suc h, it is protected from encroac hmen t. 9.1 State

f

conserv ation

f

buildings, instrumen ts and arc hiv es Most

f

the buildings are regularly main tained but certain

f

those not in use for curren t astronomical pro jects require restoration. In particular, the Gill Rev ersible T ransit Circle building

f

iron and steel is in p

r

condition. The arc hiv es and retired instrumen ts are generally w ell-protected from en vironmen tal dammage. 9.2 Restoration and/or main tenance

f

the site and instrumen ts Certain

f

the

ld

instrumen ts ha v e recen tly b een restored. These include the Merz 7-inc h telescop e and the de la Rue photoheliograph. A m useum in the former McClean lab

ratory

con tains a selection

f

the smaller an tique instrumen ts no longer in use, ranging from a Dollond Rep eating T ransit used b y F allo ws to the photometry equipmen t

f

A.W.J. Cousins. 10 Buer zone The Ro y al Observ atory site is partly ank ed b y preserv ed w etlands and the lo w er parts

f

the site itself are sub ject to

ccasional
ding,

making them unsuitable for dev elopmen t. 10.1 Con text and en vironmen t, landscap e The site is no longer dark and rural. Bey

nd

the b

undaries
f

the Tw

Riv

ers Urban P ark it is surrounded b y freew a ys and ma jor roads,

ce

buildings etc. 10.2 Arc haeological/historical/heritage researc h The Ro y al Observ atory is w ell do cumen ted historically in b

ks

b y Gill and W arner and b y man y articles in b

ks

and journals. Researc h

n

historical matters b y v arious in terested parties is fairly con tin uous. There is a k een in terest in the history

f

the site and recen tly an indep enden t \F riends

f

the Observ atory" group has b een

rganised,

with restoration

f
ld

instrumen ts and domes as a ma jor theme. An application to the South African National Heritage Agency is curren tly in progress. If appro v ed it w

uld

b e the rst SA cultural so designated for its scien tic researc h history . 11 Main threats

r

p

ten

tial threats to the site The main threat to the Ro y al Observ atory site lies in the ev er-increasing pressure

n
p

en urban land from real-estate dev elop ers. 12 En vironmen tal study Curren tly , an Observatory Baseline Information Study has b een commissioned to b etter analyse the natural and urban en vironmen t

f

the site and b etter c haracterise its unique prop erties, with a view to preserving them. 13 Outreac h F

r

man y decades there has b een a public

utreac

h programme. Op en nigh ts are held mon thly

r

more

ften,

in whic h mem b ers

f

the public are giv en free

f

c harge an in tro duction to the Observ atory , a lecture

n

an astronomical topic and sky-viewing

pp
rtunities.

In addition, man y sc ho

l

and

ther

groups tour the establishmen t during the da ytime. 4