coal as the wire rope tugs when doing the same work under the same
circumstances. The screw tugs just mentioned have a draught of 2½ meters
(8 feet 2½ inches), and are fitted with engines of 560 indicated horse
power.

During the years 1879, 1880, and 1881, the company had in use fourteen
paddle tugs and ten eight-wire rope tugs, both classes being--owing to
the state of trade--about equally short of work. The results of the
working during these years were as follows:

================================================================
| | Freight | Cost of | Degree
| | hauled | haulage in | of
Class of tugs. | Year. | in | pence per | occupation.
| | ton-miles. | ton-mile. |
----------------------------------------------------------------
Paddle | 1879 | 31,862,858 | 0.1272 | 0.686
" | 1880 | 31,467,422 | 0.1305 | 0.638
" | 1881 | 28,627,049 | 0.1245 | 0.537
Wire Rope | 1879 | 15,407,935 | 0.1167 | 0.614
" | 1880 | 17,289,706 | 0.1056 | 0.615
" | 1881 | 17,593,181 | 0.0893 | 0.536
================================================================

The last column in the above tabular statement, headed "Degree of
Occupation," may require some explanation. It is calculated on the
assumption that a tug could do 3,000 hours of work per annum, and this
is taken as the unit, the time of actual haulage being counted as full
time, and of stoppages as half time. The expenses included in the
statement of cost of haulage include all working expenses, repairs,