MARCH 21, 1884. | 
five hundred pounds by the legislative council. In 
all, a sum of about nineteen hundred pounds was 
contributed. 
Under the superintendence of Mr. Robert Pett, of 
the Cape observatory, the new establishment was 
constructed, and the instruments erected. On the 
1st of December, Mr. Neison took possession of the 
observatory as astronomer to the Natal government, 
and subsequently the observatory was taken over by 
the government of the colony. It lies on the south- 
west corner of the land originally granted for the 
use of the botanic gardens, and is a substantially 
built, rectangular red-brick building with cement 
facings, and carries a light wooden upper structure, 
forming equatorial and transit rooms. At present, 
there being no protection from the direct rays of the 
sun, the substantial walls of the observatory become so 
hot in the day, that it will be difficult to obtain proper 
observations until the building is completed by the 
erection of a veranda to shield the walls, and prevent 
their becoming so intensely heated. Having,become 
thus raised in temperature during the day, the walls, 
owing to their massiveness, require the greater por- 
tion of the night in which to cool ; and during this 
time they give rise to convection-currents of heated 
air, which render it difficult to secure satisfactory 
observations with any of the instruments. 
At the time of Mr. Neison’s report, the principal in- 
struments of the observatory were: a fine eight-inch 
equatorial (by Grubb), the gift of Harry Escombe, 
Esq. ; a high-class three-inch transit instrument, 
purchased by the government; an excellent sidereal 
clock, originally constructed for the Royal obser- 
vatory, Greenwich, and at present lent by the Tran- 
sit of Venus commission to the astronomer; and two 
chronometers, the one a sidereal, and the other a 
mean time. Mr. Neison describes these instruments, 
and reports their satisfactory performance. The ob- 
servatory is at present without the usual equipment 
of meteorological instruments, but they will be ob- 
tained from England in the course of the spring. 
Mr. Neison remarks upon the necessity of having 
proper steps taken for transferring in a regular man- 
ner to the Natal government the observatory and its 
site. It is built on ground originally assigned for a 
botanic garden, with the understanding that a suffi- 
cient space should be set aside for the purpose as 
might be deemed sufficient by the astronomer, though 
no written agreement to that effect was thought 
necessary. Owing to the nature of the ground, — 
a hillside covered with brush, —it is imperative that 
the astronomer (for the time in charge) should have 
every authority and complete control over the ground 
to the north and north-east of the observatory, which 
must be his chief observing-region ; for otherwise he 
may be seriously hampered in carrying on his scien- 
tific work. The trees and other vegetation upon the 
surface of the ground have a far greater influence 
upon astronomical observations than in merely cut- 
ting off the view of a small portion of the heavens; 
this influence extending over the atmosphere for a 
considerable distance above them, owing to their 
liability to establish air-currents and tremors which 
SCIENCE. 
39T 
are fatal to accurate observations. Experience has 
shown it to be not unfrequently necessary to clear 
the ground of particular kinds or groups of trees and 
shrubs, which establish such currents from being out 
of harmony in temperature and radiation-constants 
with the surrounding surface. Pines, laurels, and 
rhododendrons have had, on this account, to be 
removed from the environs of more than one obser- 
vatory. Even the watering of the ground will give 
rise to most injurious convection-currents at times. 
When the moisture is general, as after a rain or 
heavy dew, it is of far less consequence; but when it 
is partial, as in watering plants, each plant sets up 
its own convection-current, and thus causes objects 
to appear most unsteady when seen through the air 
above, and so ruins accurate observation. Taking 
all things into consideration, Mr. Neison regards it 
as certainly most unwise to cramp the observatory 
and its future by confining the site set apart for its 
use to a smaller area than three hundred by seventy 
yards, both measured horizontally. A mere partial 
control or divided authority over this area, or any 
portion of it, would be unwise; for it would be sure 
to lead to complications and conflict of authority — 
if not in the immediate future, for a certainty at no 
long-distant date. 
The Natal observatory has taken vigorous measures 
for the distribution of time-signals throughout the 
colony. At one o’clock every day a signal is sent to 
the central telegraph-office at Durban, from which 
it is distributed all over the colony, firing a time-gun 
and dropping a time-ball at Maritzburg, and also one 
at the Point, Durban. It is proposed to extend this 
system by the addition of a time-gun in the centre 
of Durban; to establish time-balls at Newcastle and 
Stanger; and, in connection with the Natal harbor 
board, to establish a system for properly regulating 
and rating ships’ chronometers, similar to that al- 
ready in existence at Liverpool and elsewhere. 
In observing the transit of Venus the astronomers 
were moderately successful, no observations being 
undertaken outside of the usual optical ones. Copies 
of all the observations have been duly transmitted, 
through her Majesty’s astronomer at the Cape, to 
the Transit of Venus committee at Burlington house, 
London. 
With regard to tidal reductions, it has been ar- 
ranged with the Natal harbor board that the tidal 
observations which are being made at Natal shall be 
reduced in the colony under the superintendence of 
the observatory, and proper tidal-tables constructed. 
With reference to the future work of the obser- 
vatory, it is proposed to take advantage of every 
opportunity for carrying out a series of observations 
of the moon, with a view of obtaining data for per- 
fecting the tables of the motion of our satellite. The 
duty of making standard meridian observations of 
the moon is fully carried out at the Royal obser- 
vatory, Greenwich, and partially at the Radcliffe 
observatory, Oxford, and at the U. S. naval obser- 
vatory, Washington ; but, for obtaining the full 
information necessary for properly discussing these 
observations so as to make them available for per- 
