TRANSACTIONS OF THE SECTIONS. 169 
that without great capital and indomitable industry such a load could not long be 
sustained. 
Concluding remarks.—Notwithstanding all the drawbacks above hinted at, Glasgow 
still seems destined to advance in a ratio as prodigious as heretofore. At this moment 
a new town is being added to its western and northern boundary ; streets, squares and 
crescents rise on every hand: a dozen of new spires, surpassing in architectural beauty 
the steeples of the old established kirk, formerly the monopolist of such structures, 
are shooting up in every direction, to give character and beauty to the city. The 
ancient bridge, which, previous to the erection lately of Hutcheson’s and the Glasgow 
bridge, was for nearly six centuries the only communication between the north and 
south sides of the Clyde, has been just swept away to make room for a granite struc- 
ture, equal in breadth to London Bridge. The deepening-machine and the diving- 
bell are daily labouring to maintain and increase the depth of the river. A thousand 
minds are nightly dreaming either of new combinations of forms or of colours to meet 
the growing taste of an advancing world, or are devising new mechanical appliances 
to diminish labour and ease mankind of toil. The manufacturer is still increasing 
his spindles and his looms, the merchant is still looking out for new products and new 
markets, while hundreds are flocking from all quarters of the land, full of hope or of 
enterprise, to join the already congregated crowd of eager competitors for labour or 
for gain. And yet, amid all this restless enterprise and activity, philanthropy is not 
asleep, for we find her engaged in raising lodging-houses for the industrious, retreats 
for the poor and the aged, houses for the houseless, hospitals for the sick, and schools 
for the ragged and the neglected; and, in fine, ministering to the sorrows and alle- 
viating the miseries of the diseased and the unfortunate, 
MECHANICAL SCIENCE. 
Tue Astronomer Royal exhibited specimens of some spare castings for the pivots 
of the large transit-circle now in preparation at the works of Messrs. Ransomes and 
May, Ipswich, for the Royal Observatory, Greenwich. These castings had been 
broken for the purpose of showing the chilled structure ; and the Astronomer Royal, 
in exhibiting them, alluded shortly to the construction of the instrument, and to the 
connexion of its general arrangement with the use of chilled iron for the pivots. The 
instrument is in form like a transit instrument carrying two large circles (one for 
graduations, the other for clamping): the axis is 6 feet long, consisting of two 
cones whose bases are attached to a cube of 20 inches; the telescope is 12 feet 
long, carrying an eight-inch object-glass ; the circles are 6 feet in diameter. To 
carry an instrument of these dimensions (weighing about a ton) hard pivots are 
evidently indispensable ; but the Astronomer Royal had been taught by experience 
to put no trust in the connexion of pivots of one material with an axis of another 
material; and he would therefore scarcely have ventured on the construction 
of an instrument of this magnitude, unless he had been able to find a material 
which, in different parts of the same flow of metal, could be made soft and easily 
workable in one part, and hard in another. It was at Mr. May’s suggestion that 
cast iron was adopted, the pivots being “chilled.” This process (which, as the 
Astronomer Royal believed, was either invented or was first extensively introduced by 
the senior Mr. Robert Ransome, for the purpose of hardening one side only of cast- 
iron plough-shares, so that in their wearing they may always preserve a sharp edge) 
consists in casting the iron in a mould of iron which is heated to a degree known by 
experience to be the most favourable for hardening the cast. [In the specimens 
which were produced, the pivots were hardened to the depth of about half an inch, 
and to this depth the iron is so hard as to be scarcely touched by a file.] The axis, 
including the central cube, the two cones, and the two pivots, was formed in two 
casts (their line of separation bisecting the cube). Each of these was cast ina mould, 
of which all that included the semi-cube and the cone was of sand, while that part 
which included the pivot was of iron. The joining surfaces were planed, and the 
cones were turned, in the usual way, but the pivots were ground with emery; and 
