Navigable river

“ It is essential to know the heaviest flood discharge of any river that may flow into an estuary, the greatest depth and velocity of the river, the normal and flood channels, their sectional area and direction, and the extent and shape of the catchment area, so as to establish the required opening to give the natural waterway; for it is important not to interfere with the tidal capacity of an estuary or the volume or flow of any upland waters into the sea, as a navigable 172channel may become filled with silt, especially when the shore is flat or sandbanks exist ”

“ Navigable rivers unite rather than separate, for the obvious reason that they generally flow through populous valleys, and the vessels that pass up and down can touch as easily on one side as the other. ”

“ There is a narrow neck of land separating the river from the ocean, through which an artificial channel might be opened without a great deal of labor, giving a much better entrance than across the present rocky bar of the outlet to the sea. Should the resources of the country warrant this proceeding, it looks as if it would be entirely practicable. After passing the bar the river is deep, and well adapted to navigation for eight or ten miles, up to the mouth of the Rio Prata, and thence the last-named is said to be navigable for twelve miles. ”

“ When the steps or rocky barriers are very high, and entirely bar the river, light boats are carried on shore, and with the help of branches of trees placed under them to serve as rollers, they are drawn as far as the place where the river again becomes navigable. ”

“ The examination of its vast interior can only be performed by degrees: want of navigable rivers will naturally impede such a task, but all these difficulties will be gradually overcome by the indefatigable zeal of our countrymen, of whose researches in all parts of the world the present times teem with such numerous examples. ”

“ Eventually, large rivers, under favourable conditions, often furnish important natural highways for inland navigation in the lower portion of their course, as, for instance, the Rhine, the Danube and the Mississippi; and works are only required for preventing changes in the course of the stream, for regulating its depth, and especially for fixing the low-water channel and concentrating the flow in it, so as to increase as far as practicable the navigable depth at the lowest stage of the water-level. ”

“ As the dividing channels of the lower course point to the feasibility of amplifying the connection with the ocean highway, so the spreading branches of a river's source, which approach other head waters on a low divide, suggest the extension of inland navigation by the union of two such drainage systems through canals. Where the rivers of a country radiate from a relatively low central watershed, as from the Central Plateau of France and the Valdai Hills of Russia, nature offers conditions for extensive linking of inland waterways. ”

“ Good roads, canals, and navigable rivers, by diminishing the expense of carriage, put the remote parts of the country more nearly upon a level with those in the neighbourhood of the town. They are upon that account the greatest of all improvements. ”

“ The mouth of a large river system is the converging point of many lines of inland and maritime navigation. The interests of commerce, especially in its earlier periods of development, demand that the contact here of river and sea be extensive as possible. Nature suggests the way to fulfill this requirement. The sluggish lowland current of a river, on approaching sea level, throws out distributaries that reach the coast at various points and form a network of channels, which can be deepened and rendered permanent by canalization. ”

“ In the wildest parts of the best rivers the channel is too narrow for oars, or, if wide, it [2] is too shallow for a row-boat; and the tortuous passages, the rocks and banks, the weeds and snags, the milldams, barriers, fallen trees, rapids, whirlpools, and waterfalls that constantly occur on a river winding among hills, make those very parts where the scenery is wildest and best to be quite unapproachable in an open boat, for it would be swamped by the sharp waves, or upset over the sunken rocks which it is utterly impossible for a steersman to see. ”

“ I declared to the open marshes, as I set foot out upon the raised way which led over to the Habitants Ferry.
The ferry-boat which crosses the deep and turbid tide of the Habitants is a clumsy scow propelled by a single oar thrust out from the stern. The river is hardly passable save for an hour on either side of full flood. The rest of the time it is a shrinking yet ever-turbulent stream which roars along between precipitous banks of red engulfing slime. ”

“ This mole stretched its long strong low back to a rock a good way out, breaking the force of the waves, and rendering the channel of a small river, that here flowed into the sea across the sands from the mouth of the canal, a refuge from the Atlantic. But it was a roadway often hard to reach. In fair weather even, the wind falling as the vessel rounded the point of the breakwater into the calm of the projecting headlands, the under-current would sometimes dash her helpless on the rocks. ”

“ John pours out its great flood into the harbor. An immense body of water passes through this channel, representing the natural river drainage of over 25,000 square miles of country. It is not a fall as ordinarily understood, nor a sheer drop from high to low level. The outlet, though wide, is not sufficiently large to admit the inflow of the tidal water. The tide packs up, therefore, and falls into the river. In the same way the tide recedes in the harbor much faster than it can escape from the river channel, and at such time the fall is outward. ”

“ We see the high, steel cable strung across the river, with the running block and gang ropes connecting it with the side-railed flat barge or ferry. These floats are often propelled across stream by the force of the current. Just as a ship makes headway by the side wind running off her sails obliquely, so does a boat cross a stream by the action of the tide, if care is taken to have the boat’s head turned partly against the current. ”

“ Several years ago the whole distance from our homes to the interior was traveled by water, on which occasions heavy-laden boats were taken up these rivers and streams, and across the lakes, an operation which was both hazardous and laborious, particularly where the swift current of rapids was to be overcome, and when it became necessary to carry the boat and cargo around impassable falls—a frequent occurrence, the river in some places being nothing but one continuous succession of rapids for miles. ”

“ In this position we pass over the same route through which the provisions have been carried to the next landing, where the goods are again reshipped, and we proceed by water on lake or stream, with the alternate routine of paddling, poling, and lugging, until the place of destination is reached.
Persons wholly unacquainted with river navigation can have but an imperfect idea of the skill as well as nerve brought into requisition in taking a heavy-laden bateau, skiff, or canoe up over rapids. ”

“ It is not easy to describe the labour of such navigation. We must prevent the waves from dashing the boats against the cliffs. Sometimes, where the river is swift, we must put a bight of rope about a rock, to prevent her being snatched from us by a wave; but where the plunge is too great, or the chute too swift, we must let her leap, and catch her below, or the undertow will drag her under the falling water, and she sinks. ”

“ Hence the rivers are navigable only for short distances, and even then only exceptionally by large vessels. It is only in those comparatively frequent cases where the rivers expand into lakes that they can, strictly speaking, be navigated by ships. ”

“ The formation and keeping open of large estuaries are due to the combined influence of tidal currents and rivers; for when the tide rises, a large body of water suddenly enters the mouth of the river, where, becoming confined within narrower bounds, while its momentum is not destroyed, it is urged on, and, having to pass through a contracted 338 channel, rises and runs with increased velocity, just as a stream when it reaches the arch of a bridge scarcely large enough to give passage to its waters, rushes with a steep fall through the arch. ”

“ I saw men and women fishing in the broad river, and to my amazement found their boats were literally rafts—wooden logs bound together by ropes or thongs of leather and fibre. Hardly had I perceived this before the thought and hope flashed through my mind that on some such vehicle of transit I could trust myself to the stream, and that it was most likely that these hardy highlanders could give me the information I now needed as to the channel, direction, debouchment, and navigableness of the noble water in its course to the coast. ”

“ Among various other conditions of river navigation may be mentioned—the extremely serpentine courses of some of the rivers, two miles often having to be made for each mile of real advance; the ever-varying channels in some of the streams; the arduous labour of towing against strong currents, especially when, in the absence of towing-paths for horses, this work had to be done by men; and the destruction, by floods, of the river banks or of works constructed on them. ”

“ Where streams are large enough to be navigable industrial considerations often prevent the utilization of their power, the streams being more serviceable as highways than as sources of power. Other things being equal, it follows that streams are most available for water-power when they are large enough to have a moderately steady flow, and not so large as to be beyond ready control, or to be valuable for purposes of navigation. ”

“ Now the strip of water widens and very slowly we move from the quay, being dragged ignominiously backward [Pg 24] across the great basin in which we lie by a diminutive steamer called a tug. We are not out in the river yet and our own engines have not begun to work. You can understand that it would be very difficult to load a ship if she stood always in the river, where there are rising and falling tides, so, to make this easier, great docks have been built along the river, and in them the flow of the tides is regulated, so that the water remains always at pretty much the same level. ”

“ From the books which they had read the boys had learned that there is, if anything, more fun in cruising on a narrow stream than in sailing on broad rivers; that running rapids is a delightful sport, and that streams should always be descended instead of ascended in a canoe. They therefore wanted to discover a narrow stream with safe and easy rapids, and also to cruise on some lake or wide river where they could test the canoes under sail and under paddle in rough water. ”

“ More to the purpose of the present moment, the government engineers have expelled the quicksands and confined the waters so that from the vagaries of running waves of sand and shallow films of water, true channels have been forced through, and the old two or three feet of available low-water depth has been increased to eight or ten feet, practically guaranteed up a thousand miles of river. ”

“ The causeway which might therefore be necessary to approach the stream from the south in all states of the tide need only have been such a hardening of the track over the mud as is necessary between the high- and low-water mark of any tidal river where a ferry is to be established, and we must believe that the river at high water washed the gravel spit. ”

“ The stream, which, like nearly all Martial rivers, is wide and shallow, had during the last fifty miles of our course grown narrower, with a depth at the same time constantly lessening, so that some care was required on the part of the pilot to avoid running aground. A stream of twenty inches in depth, affording room for two boats to pass abreast, is considered navigable for vessels only carrying passengers; thirty inches are required to afford a course which for heavy freight is preferable to the road. ”

“ Rivers have always been the great intermediaries between land and sea, for in the ocean all find their common destination. Until the construction of giant steamers in recent years, sea navigation has always passed without break into river navigation. ”

“ Water gave us our over-sea commerce, that came in and went out by way of our tidal rivers; and the step proposed toward the fostering of our home industries was a great one when it occurred to somebody to imitate nature, by erecting artificial rivers that should flow whereever we wished them to flow, and should be navigable along their whole course for capacious, flat-bottomed carrying-boats. ”

“ The stream which cuts your trail is not always provided with bridges of fallen trees. It may be a river too deep to ford and too wide to be bridged by a chance log. Of course it is a simple matter to swim, but the weather may be cold and the water still colder ”

“ When the tide begins to flow up the river there may be a low-level salt water current moving landward and a high-level fresh water current moving seaward, but this is quite a temporary state of affairs. The surface slope is landward, and the water moving seaward is not moving in obedience to the surface slope. ”

“ The improvements that have been carried out for the purpose of opening up the navigation of the river Tees, although less considerable than those carried out for some of the larger rivers of Great Britain, are yet entitled to take rank as among the most notable river engineering achievements of the century. ”

“ One of these systems depends upon gaining an impulse or hold against the ground at the bottom of the river or canal, in one of which a small boat moved by oars was proposed to be employed in successively carrying forwards and dropping anchors whose ropes were to be attached to a horse-gin, on board of a barge, which was designed to tow or drag a great number of others. ”