at the Cape of Good Hope. 87 
There had been, for some time, a Royal Observatory at the Cape, 
belonging to the British government, under the direction of 
Thomas Maclear, Esq., an able and accomplished astronomer, 
whom Sir John received every courtesy and assistance it 
was in the power of that gentleman to afford him. But, in his 
ordinary labors, Sir John had only the aid of an assistant whom 
he had trained in England, not only in “ working and sweeping,” 
but also in executing various mechanical operations essential to 
labors of this description. “'This indispensable manual aid except- 
ed, (says our author, ) it is right to mention that the whole of the 
observations, as well as the entire work of reducing, arranging, 
and preparing them for the press, has been executed by myself. 
‘The repolishing of the reflectors it will of course be understood, 
could be delegated to no other person.” 
_. When we first opened this ponderous volume, and glanced over 
its pages, we could have scarcely believed on any other authority 
than that of the author himself, that such a vast number of the 
Most refined and difficult observations as it records, and such im- 
‘Mense labor as their reduction must have involved, could have 
been the work of a single individual. To say nothing of the 
consummate skill evinced on every page, the patient toil and un- 
tiring perseverance implied in this work would have done honor 
to Kepler himself. 
_ Sweeping in arcs of 3° of North Polar distanees, was prose- 
ecuted in the absence of the moon on all occasions when the 
Weather permitted, and the definition of the stars was such as to 
tender it worth while to do so. The climate of the Cape, in 
1erence to astronomical observations, Sir John Herschel repre- 
Sents as on the whole very favorable, especially when compared 
with the foggy atmosphere of England. This is particularly the 
ase in the cooler months from May to October, when the state 
of the air, in respect to definition, is habitually good, and imper- 
fect vision is rather the exception than the rule. The best nights 
occur after the heavy rains, which fall at this season, have ceased 
for a day or two. On these occasions, the tranquillity of the im- 
ages, and the sharpness of vision, is such, that hardly any limit is 
Set to magnifying power, but what arises from the aberrations of 
_ The author concludes his ‘ Introduction” with a just tribute 
to the late Duke of Northumberland, and informs us that, to the 
munificent donation by his Grace of a large sum in aid of the 
publication of this work, it owes its appearance asa single and 
Separate work, instead of a series of unconnected memoirs, scat- 
tered over the volumes of academical bodies. The lamented 
se of that illustrious nobleman, prevented his witnessing its 
mpletion ; but his liberal intentions have been fully carried 
“by his successor to his titles and his spirit.” 'The whole 
1onWealth of astronomers, we are confident, will share with 
