THE EXHIBITION OP 1862. 
71 
have been taken as it were in relief, — transferred by electro- 
metallurgy to a solid form, and, dispensing altogether with the 
engraver’s aid, printed from in the ordinary manner. The 
binocular microscope has given a fresh impetus to the study of 
nature in its most minute and intricate forms. Telescopes, 
indeed, there were in abundance, and good ones too, at the 
last Exhibition, but they have since been exceeded in power 
and excellence, although, with the exception of Foucault’s suc- 
cessful contrivance of silvering a parabolic glass surface, nothing 
novel has been introduced in them construction. In the matter 
of reflecting telescopes with metal mirrors, the movement has 
been retrograde ; but even this, perhaps, has been judicious. 
At the epoch of the Exhibition of 1851, Lord Eosse’s six-foot 
reflector was in full operation — disclosing the wonderful spiral 
structure of several nebulae, resolving others, and thus connect- 
ing them, in different respects, with the form and nature of our 
own Milky Way. But the labour of years bestowed upon its 
construction, and the difficulty of keeping its polished surface 
in proper condition, have not been found sufficiently fruitful in 
results to warrant the extension of this description of telescope. 
Only one telescope of large dimensions has since been con- 
structed on this plan, — the four-foot mirror of Mr. Lassell, 
from which, doubtless, by aid of the clear sky of Malta and the 
long experience of the maker and observer, great results may 
be anticipated. It is remarkable, that it has been the makers 
of reflecting telescopes who have been most successful in celes- 
tial discovery, — the two Herschels, Lord Eosse, Mason, and 
Lassell, are striking instances of this, — but the care required to 
keep them in working order, already alluded to, has caused 
astronomers to have recourse once more to the original refract- 
ing telescope, and the latter has gained considerably by the 
preference. Separate instruments for meridional observation 
(on a large scale) do not figure at the Exhibition of 1862. 
Thanks to the present Astronomer Eoyal, the transit instru- 
ment and mural circle have been united into one solid apparatus, 
with which a single observer can do the same work much more 
satisfactorily than two on the old system, and register the right 
ascension and declination of an object with the same ease and 
equal certainty as on the ancient plan. 
The electric telegraph is now a domestic institution, vastl_y 
simplified, but yet capable of further improvement, particularly in 
the insulating of the submarine cable ; for out of 14,000 miles 
already laid down, only 4,000 are stated to be in working order. 
It would be impossible, within the limits of a short summary 
such as the present, to go seriatim through the various objects 
exhibited by one hundred and fifty different inventors and 
manufacturers. Tn those articles where taste an d ornamenta- 
