m 



WATERING OK LAND. 



M 'AYES AND TIDES. 



77J 



young or okl plants, in poU or in the open ground, the watering 

 of the plant is always recommended. 



In w.<!.nng pUnU . \.r.,l instruments are made uw of, the 

 engine, the i the watering-pot These are made either to 



throw water through tu> c of Titrioua tan so u to apply the water to 

 a particular |>int, or l>y mcana of a race which is appended to the tube 

 to distribute the water over a larger surface. The former method is 

 adopted when the root* of a plant are to be watered, and the latter 

 when it is wished to wet the whole surface. Where a stream can be 

 made use of, an effectual way of watering plant* is to have a !' 

 which the water of the stream may be let on and off as may be thought 

 proper. This is the best mode of watering water-creases and . ti,. r 

 planto requiring abundant moisture. Where there are water-works, 

 pipes are sometimes laid for supplying rmnpcirtmcnU of a garden. 

 Lawns and plots of grass may be watered from the water-butt. 



WATERING OK LANK [luni.JATiosr.] 



WATERMAN, one who rows a boat on a river for the conveyance 

 of passengers. The only large body of watermen in England are 

 those employed on the river Thames at London. Before the intro- 

 duction of coaches they were a very essential clara for the conveyance 

 of persons not inly l.-tweiii London and .Southwark, but between 

 London : n>l Westminster, and up and down the river to the various 

 places on eacli .- ide. The Thames was then the ."rent highway. Stairs 

 and watergates were numerous on the north bank from London to 

 WestniinMer. v, here there were many palaces of the nobility, eneh 

 palace having its landing-place, its barges and wherries, and its pri- 

 vate retinue of watermen, or bargemen, as they were then commonly 

 called. Processions on the river, water-tournaments, boat-races, and 

 other aquatic amusement) were frequent. In the reign of Hichard II. 

 the fare for a passenger, with his truss or farthcll, from London 

 to Graveseud or Milton, was '2<l. Stow computes that there were 

 as many as 2000 boats in his time, that there were 40,000 water 

 men on the rolls of the Watermen's Company, and that they could 

 furnish 20,000 men for the fleet. No doubt he included in this large 

 number the private watermen of the court and the nobility. John 

 Taylor, the " water-poet," as he styled himself, complains bitterly of 

 the introduction of coaches : " I do not inveigh against any coaches 

 that belong to persons of worth cr quality, but only against the cater- 

 pillar swarm of hirelings. They have undone my poor trade whereof 

 I am a member." Since that time the increase in the number of 

 bridges and the introduction of steam-boats has reduced the watermen 

 to a comparatively small number. 



An apprenticeship of ecven years on the Thames constitutes a free 

 waterman. The watermen and lightermen are an incorporated com- 

 pany, founded in 1556, and regulated partly by their own bye-laws and 

 partly by 7 & 8 Geo. IV., c. 75. With the exception of certain flat- 

 bottomed ferry-boats and barges above Kingston, no person can ply in 

 a boat for hire on the Thames who is not a member of the Watermen's 

 Company. 



The Trinity House has, however, power to license certain king's 

 seamen, besides pilots, to ply on the river. 



WATERS. MINERAL. [ ARUTKD WATXM,] 



WAVE. [WAVE* AND TIUI s ] 



WAVES and TIDES possessing in many respects the same charac- 

 ter, it bos been thought proper to state in one article the phenomena 

 and the theories of both. 



From the earliest times the periodical risings and fallings of the 

 waters on coasts or in rivers have been noticed ; and the recurrences of 

 the phenomena depend so obviously on the positions of the moon and 

 tun, that the influences of those celestial bodies in producing them 

 have ever been assigned as their cause. The tide appears as a general 

 rave of water which gradually elevates itself to a certain height, then 

 u gradually sinks till its surface is about as much below the medium 

 level a* it was before above it : from that time the wave again begins 

 to rise ; and this reciprocating movement of the waters continues con- 

 stantly, with cerUiu variations in the height (with re.-peet to the mean 

 level), and in the times of attaining the maxima of elevation and 

 depression. 



Ordinary waves are produced by any cause which disturbs the equi- 

 librium of the particles of a fluid. Thus, a stone suffered to fall into 

 water at rest gives rise to a series of concentric circular waves < 

 Ing to a gn-at distance from the place where the stone falls j and in .1 

 canal the fall of a body of water from a level above that of the general 

 surface will produce a series of waves advancing along the canal 

 Waves are also produced by suddenly pressing a solid into water, or by 

 suddenly withdrawing it from thence ; and a single wave may be caused 

 by paitly immersing a solid body in water and moving it quickly, for a 

 -n a horizontal direction. The inequalities of the pressure of the 

 air on the surface of water, whether at rest or in motion, when a gentle 

 wind is blowing, will produce tipple*; and if the action bo continued 



he ripples, at a certain distance from the place of theii 

 become considerable waves. In the open seas the heights of the 

 depend on the force of the wind ; but in confined situations both the 

 heights and forms of the waves are affected by the resistance 

 bed, by reflections from the shores, and other circumstances. When 

 waves are formed by wind blowing from the land, each wave-summit 

 preserves constantly the same height ; but tho heights go on increasing 

 with the distance from the shore. 



Wind-waves appear generally to bo of a cycloidal form : their sum- 

 mits have a gentle curvature, while the height bears a small proper- 



i tion to the length in the direction of the motion ; but as the i 

 increases, the summit becomes moro. acute, and assume* the form of a 

 ridge ; and when this becomes too sharp for the preservation of equi- 

 in, tho force of the wind acting hori/ontolly near the top breaks 

 it into foam or spray [col. 788 of the present article. The nature of 

 tin- spray itself has been noticed in WATERFALL*.] As waves advance 



i toward* a shore, the water becoming less dee]), the resistance of the 

 1 '-.l of the sea oaiises their lengths to diminish, and at the same time 

 tlieir heights to increase, so that the front of the wave becomes steep ; 

 mid the motion of tho upper part, towards the land, being more rapid 

 :!. n that of the lower port, it follows that the summit U carried beyond 



I the base ; and, falling forward, there is produced what is called a surf. 

 The breaking of waves over a sunk shoal depends chiefly on a like 

 canoe. 



The surface of the sen often presents very complex phenomena. It 

 may happen, for example, that while a long swell resulting from some 

 distant storm is advancing in one direction, a breeze will produce a 

 series of waves moving in the direction of the wind ; and a second 

 breeze springing up in another direction will produce a new series, 

 which will become mixed with the former without destroyin th.-m : 

 a third gale may also produce a system of waves intersecting the other 

 systems. When a breeze has been blowing for some time from a cer- 

 tain quarter, and afterwards changes to the opposite, two series of waves 

 may be seen moving in contrary directions ; and if the waves are 

 nearly of equal lengths, the vertical ordinatus at the crest of the com- 

 pound wave will be equal to the sum or difference of the ordinates of 

 the simple waves, according as the crests are coincident, or fall in each 

 other's intervals. These phenomena are indicated in the first and 

 second of the subjoined figures, where a 6 represents the first undu 



and a,' V the second, the straight line A B being the horizontal surface of 

 the water when at rest. Again, when there exists a third system of 

 waves, caused, for example, by reflection from a coast, so as to be 

 parallel to the two former systems, the combination of the three 

 systems has been observed to produce a compound wave of the form 

 represented in the third figure. (' Report of the Committee of the 

 British Association on Waves.') 



The wind-waves of the sea do not extend to considerable depths. 

 From the experiments made by the committee appointed by the I 

 Association in 183ti, it was found that with a depth < inal to 



12 feet, waves 9 inches high and 4 or 5 feet long did not sensibly affect 

 the water at the bottom. Waves from 30 to 40 feet long, oscillating 

 at intervals of 6 or 8 seconds, produced some effect, but much less than 

 near the surface : and it was ascertained that, in waves produ 

 the wind on the surface of a deep sea, the velocities were not :i 

 function of the depth. In a storm tho sea is probably tr.ui.nii! at the 

 depth of 200 or 800 yards. The most satisfactory measurements, 

 those of the late Rev. Dr. Scoresby (' Iteport of British Assoei 

 1850, ' Journal of a Voyage to Australia '), give, for the height of the 

 highest waves, 43 feet, from bottom of trough to crest. 



It must not be imagined that when water ia agitated by waves, its 

 whole moss has the movement which at first sight appears from the 

 observed progressive motion of the undulation; and, in order to 

 account for the formation and motion of waves, it is sufficient to assume 

 that the particles of water, when disturbed, have merely small oscilla- 

 tory motions in horizontal and vertical directions. When, from any 

 cause, as the fall of a stone into it, the water becomes agitated, .> 

 of horizontal motions to and fro ore produced ; and while in a . : 

 vertical column of water these motions arc equal and in one div 

 the surface neither rises nor falls ; but if, in two neighbouring columns, 

 the particles advance to meet each other, tho water becoming 

 pressed, the surface rises; if the particles recede from one .mother, 

 those above descending by gravity, the surface falls. These different 

 horizontal movements existing successively in the same vertical column, 

 and simultaneously in those which arc adjacent to each other, thn sur- 

 face of the water becomes undulated. In order, however, to under- 



stand the true movements of waves, let the straight line at represent 

 the surface of water when undisturbed, and, disregarding the hori- 



