he introduction of a resistance between any section of the line and
the supply of electricity. The speed may be high, as much as 1500 ft.
per minute over the straight portions of the line, but slackened at
curves and loading stations, or when approaching a terminus. The
required power may be obtained from the mains of an ordinary electric
supply with either direct or alternating current, but the former is
preferable. The mean expenditure of power in a working day is said to
average (including electrical hoisting) 1 H.P. per ton of average load.

The uses of telpherage are many and various. In factories and
warehouses, where the buildings are scattered, it has been installed
with excellent results. Being essentially an overhead system, there is a
saving of floor space, the ground not being obstructed by trucks or
trolleys. The same reasons which render ropeways an economical means of
handling such material as coal, ore, stone, slate, &c., between the mine
or quarry and the rail or barge, may be adduced in favour of telpherage.
For the unloading of railway trucks in a crowded goods-yard it is
undoubtedly applicable. Any kind of tipping or hoisting operations can
be automatically effected by its aid, and any sort of grab may be used
in dealing with such materials as sand, clay or gravel. Telpherage is
clearly a labour-saving method of handling materials, but of course the
exact conditions under which any system is to be used need careful
study, while the economy to be effected by the installation of a telpher
line must to a great extent depend upon the available supply of
electrical energy. (G. F. Z.)

FOOTNOTE:

[1] The illustrations in this article are taken, by kind permission,
from the _Proceedings of the Institution of Civil Engineers_.

CONVOCATION (Lat. _convocatio_, a calling together), an assembly of
persons met together in answer to a summons. The term is more usually
applied in a restricted sense to assemblies of the clergy or of the
graduates of certain universities.

In the American Protestant Episcopal Church a convocation is a voluntary
deliberative conference of the clergy; it has no legislative function,
and like the convocation of a university, assembles primarily to discuss
matters of common interest.

In England the name "convocation" is specifically given to an assembly
of the spirituality of the realm of England, which is summoned by the
metropolitan archbishops of Canterbury a