From some interesting data which have been placed at our disposal by Mr. Thomas Schwarz, the manager of the Central Actien-Gesellschaft fur Tauerei und Schleppschifffahrt, we learn that in the tugs Nos.  I. to IV. the hauling machine develops on an average 150 indicated horse, while in the tugs No.  V. to VIII. the power developed averages 180 indicated horse power.  The tugs forming the first named group haul on an average 2,200 tons of cargo, contained in four wooden barges, at a speed of 41/2 kilometers (2.8 miles) per hour, against a stream running at the rate of 61/2 kilometers (4.05 miles) per hour, while the tugs Nos.  V. to VIII. will take a load of 2,600 tons of cargo in the same number of wooden barges at the same speed and against the same current.  In iron barges, about one and a half times the quantity of useful load can be drawn by a slightly less expenditure of power.

The average consumption of coal per hour is, for tugs Nos.  I. to IV., 5 cwt, and for tugs Nos.  V. to VIII., 6 cwt.; and of this fuel a small fraction (about one-sixth) is consumed by the occasional working of the screw propellers at sharp bends.  The fuel consumption of the wire rope tugs contrasts most favorably with that of the paddle and screw tugs employed on the Rhine, the best paddle tugs (with compound engines, patent wheels, etc.) burning three and a half times as much; the older paddle tugs (with low pressure non-compound engines), four and a half times as much; and the latest screw tugs, two and a half times as much coal as the wire rope tugs when doing the same work under the same circumstances.  The screw tugs just mentioned have a draught of 21/2 meters (8 feet 21/2 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: 

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|       |  Freight   |  Cost of    | Degree
|       |  hauled    |  haulage in |   of
Class of tugs.  | Year. |    in      |  pence per  | occupation.
|       | ton-miles. |  ton-mile.  |
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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
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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