280 REPORT—1858. 
the cost of steam transit by the capital required to obtain a ton of capability 
for cargo, is necessarily different from that in use, as with railway or canal 
traffic in this country, viz. the cost of a ton per mile, from the absence of all 
detail of the working expenses, and the conditions of Indian river naviga- 
tion being so various and totally different from canal or even European river 
navigation. 
The valuable paper read before this Section by Mr. W. H. Bartholomew, 
the engineer of the Aire and Calder navigation, lucidly illustrated what 
economic results had been obtained by the system of tug- and tow-boats. 
The extraordinary practical results shown by Mr. Bartholomew, are not 
only honourable to those who, by the combination of practical experience 
and scientific investigation, have conduced to such important improvements 
in engines and mode of tugging, but afford the best encouragement to 
others to persevering inquiry, with the hope of introducing these improve- 
ments on the Indian rivers. 
The following is a summary of the practical results :— 
« A screw steam-tug 64 feet by 11 feet, fitted with its serew and engines, 
draws 8 or 12 tow-boats of a gross tonnage of 1240 tons, carrying 820 tons 
of cargo 23 miles an hour. Pressure of steam 200 lbs. on the square inch. 
Two screws on the same shaft, but working in a different plane of rotation, 
making 180 revolutions per minute. Dynamical effect on tow-rope, 32 ewt. ; 
consumption of coal 2 tons per day, of 10 working hours; draft of water, 
6 to 7 feet.” 
Towing cargo on the Humber, these screw tug-boats can tow and turn 
eight to twelve barges ; experience showing that the addition of two or four 
vessels reduced the speed very little in proportion to the increase of load, but 
much depended on steady steering. While on the Bengal rivers, when towing 
one very long vessel through the tortuous channels, it was found expedient 
to lash her alongside, keeping their two rudders working together, whenever 
the length exceeded 180 feet. 
Conclusion.—Having had, as commander, builder, and owner of steamers, 
thirty years’ practical experience in the establishing and working the earliest 
systems of river and ocean steamers in Bengal and the eastern coast of India ; 
and retaining up to the present time a deep personal and pecuniary interest 
in several local enterprises depending on the development of river steam 
navigation and maritime trade in Bengal; having also had much experience 
as Director of companies in this country in contracting for engines and 
steamers to meet the requirements of the Indian ports,—I believe that the 
present great difficulty of want of means of transit in India can only be over- 
come by the immediate construction of steam-tugs and tow-boats for railway, 
but separately for military and mercantile purposes. 
With a view to effective comparison of the money value of tenders and 
specifications for river steamers from different builders and contractors, I 
have used the following Table, by which the capital or cost per ton of capa- 
bility for weight-cargo can be ascertained at three drafts, as well as the 
three elements of resistance ; from these a scale or curve of displacement and 
areas can be formed, which with the indicated H. P. will afford the means of 
ascertaining the coefficient or index number of the vessel daily. 
