tidal 
Also tide-crack. Tidal friction, frictional resistance 
caused by the movement of tidal waters, tending to dimin- 
ish the angular velocity of the earth's rotation, and hence 
to lengthen the day. Tidal harbor, a harbor in which 
the tide ebbs and rtows, in distinction from a harbor which 
is kept at high water by means of docks with flood-gates. 
Also tide-harbor. Tidal motor, a mechanical device by 
which the ebb and flow of the tide are utilized as a source 
of power. Tidal river, a river whose waters rise and fall 
up to a certain point in its course under the influence of 
the tide-wave. Tidal wave, (a) The wave of the tide ; 
a great wave of translation in the ocean moving in the 
manner in which the wave of the tide moves according to 
the canal theory, but commonly produced by an earth- 
quake, (b) Figuratively, a wide-spread or general mani- 
festation of strong feeling or sentiment : as, a tidal warn 
of popular indignation. 
tidally (ti'dal-i), adv. As a tide ; in a manner 
dependent on or affected by the tide. Wincltell, 
World-Life, ii. 2. 
tidbit (tid'bit), . Same as titbit. 
tiddet. Preterit and past participle of tide 1 . 
tidder (tid'er), v. t. [Also tiddle; appar. < *tid- 
der, a., ult. < AS. tedre = OFries. tcddre = D. 
feeder = MLG. tcder, tender, weak. Cf. tid*.] 
To use with tenderness ; fondle. Johnson. 
tiddle (tid'i), D. t.-, pret. and pp. tiddled, ppr. tid- 
dling. [A var. of tidder.'] I. trans. Same&stidder. 
II. iutrans. To trifle ; potter. 
To leave the family pictures from his sons to you, be- 
cause you could tiddle about them ! 
Richardson, Clarissa Harlowe, I. xlii. 
tiddlywink (tid'li-wingk), . 1. A shop where 
money is lent on goods without a pawnbroker's 
license. Leland. [Slang.] 2. A shop where 
beer is sold without a license. Halliwell. [Prov. 
Eng.] 
tiddy 1 (tid'i), . [Origin obscure.] The four 
of trumps at the game of gleek. 
tiddy 2 (tid'i), .; pi. tiddiex (-iz). [Cf. ttrf?/2.] 
The European wren. Also tidley-icren. [Prov. 
Eng.] 
tide 1 (tid), n. [Also dial., with shortened vowel, 
tid; < ME. tide, tyde, tid, tyd, < AS. tid, time, 
hour, season, opportunity, = OS. tid = OFries. 
tid = MD. tyrf, time, tide of the sea, ylietijdc, 
time, opportunity, tijde, tijc, tide of the sea, D. 
tijd, time, getij, time, opportunity, tij, tide of the 
sea, = MLG. tide, (jetide, time, tide of the sea, 
LG. tied, time, tide, tide of the sea, = OHG. :it, 
zidh, MHG. zit, G. zeit, time, = Icel. tidh, time, 
tide, hour, service, = Sw. Dan. tid, time, sea- 
son (not recorded in Goth.): with formative -d 
(related to AS. tima, E. time* = Icel. timi, time, 
with formative -ma (see time 1 ), and to G. ziel, 
etc., end, goal, with formative -I: see till 1 , till-), 
from / ti, not found outside of Teut. Hence 
tide 1 , v., tiding, etc., betide.] 1. Time; season. 
[Obsolete except in composition.] 
If thi wijf come with a playut 
On man or child at ony tide, 
Be not to hasti to fljte & chide. 
Babees Book (E. E. T. S.), p. 51. 
He keeps his tides well. Shak., T. of A., i. 2. 57. 
This wishing a good Tide had its effect upon us, and he 
was commended for his salutation. 
Steele, Tatler, No. 178. 
2. Fit time or season ; opportunity. 
He that tas not his tyme when the tyde askee, 
But lettes it deuly ouerdryve with delling to noght, 
Wite not his wirdis, thof hym woo happyn ! 
Destruction of Troy (E. E. T. S.), 1. 7067. 
I have important business, 
The tide whereof is now. 
Shak., T. and C., v. 1. 90. 
Tide Tarrieth for no Man, a pleasant and merry comedy. 
George Wapiti (1611), title. 
[Compare the common proverb "Time and tide wait for 
no man."] 
3. Eccles., a season of the church year; in a 
narrower sense, a feast-day; a festival: as, 
Whitsuniirfe (the whole octave or the day only) ; 
Hallowiide. 
What hath it done, 
That it in golden letters should be set 
Among the high tides in the calendar ? 
Shak., K. John, iii. 1. 86. 
Tide was scrupulously used by the Puritans in com- 
Cition instead of the Popish word mass, of which they 
a nervous abhorrence. Thus, for Christmas Hallow- 
mas, Lammas, they said Christ-tide, Hallow-tide, Lamb- 
tide. Luckily Whitsuntide was rightly named to their 
hands. Nares . 
4f. Mass; office; service. 
They dwell in the lande of Armeneten nere vnto An- 
thiochyen, and there is whrythyn seruyce of the masses, 
and theyr other tydes is all in theyr one comon speche so 
that they all mey vnderstande it what they synge or rede. 
Jt. Eden (First Books on America, ed. Arber, p. xxxi.). 
5. A definite period of time ; specifically, a day 
or an hour; in mining, the period of twelve 
hours. 
He ne sholde suffren in no wyse 
Cnstance within his rcgne for tabyde 
Thre dayes and a quarter of a tyde. 
Chaucer, Man of Law's Tale, 1. 700. 
6330 
Why weep ye by the tide, lady ? 
Why weep ye by the tide ? 
How blythe and happy miffht he be 
Gets you to be his t>ride ! 
John o' Hazelgreen (Child's Ballads, IV. 84). 
6. The periodical rise and fall of the waters of 
the ocean and its arms, due to the attraction 
of the moon and sun. Every particle of matter com- 
posing the earth gravitates toward the moon inversely 
as the square of its distance, this attraction being about 
j&iAjiH! of the weight of the particle. Living upon the 
earth, we consider bodies at rest which have a fixed posi- 
tion relative to the earth. Supposing, then, what cannot 
be strictly true, that the crust of the earth experiences no 
periodical deformation of the nature of a tide, the rise and 
fall of the water as compared with a bench-mark on the 
shore will be its rise and fall relatively to the earth's 
center. Since an attraction is simply a component accel- 
eration, or rate of change of velocity, which compounded 
with others gives the resultant acceleration of the body's 
motion, it follows that the gravitational acceleration of 
the solid earth toward the moon, when all its particles 
are held rigidly together by cohesional accelerations, 
must be very nearly the same as the simple gravitation 
toward the moon of the particle at the earth's center. 
Now, we find the acceleration of a particle relative to the 
earth's center by geometrically subtracting from its abso- 
lute acceleration that of the center of the earth. Every 
particle of those parts of the surface nearest the moon is 
by the law of inverse squares more attracted to the moon 
than is the center of the earth, and consequently is ac- 
celerated upward from the earth ; and, in like manner, 
every particle of those parts furthest from the moon is 
less attracted to the moon than is the earth's center, and 
so is also accelerated upward from the earth (this causing 
the tide to rise in those parts). Thus, if ?n. is the moon's 
attraction at the unit of distance, r the distance of the 
moon from the center of the earth, and o the earth's 
semidiameter, the attraction relative to the earth's cen- 
ter, at a point of the surface where the moon is in the 
zenith, is 
m/(r a)- - m\r- = 2m/r 3 (l - air)', 
and the same where the moon is in the nadir is 
But where the particle as seen from the center of the 
earth is 90 from the moon, the attraction is a little less 
than the attraction at the center, being m/(r a -|-a s )in place 
of m/r 2 , and is also not parallel to the latter; so that it 
is accelerated downward toward the earth by an amount 
equal to ma/r 3 (l + a=/r 5 )3. Compounding these accelera- 
tions with the accelerations of the weights of the par- 
ticles, we see that the resultant for any particle points 
less toward the moon than the line from the particle to 
the earth's center. But the surface of the water must be 
perpendicular to the resultant attraction ; hence that sur- 
face must bulge out in a prolate form on the line through 
the centers of the moon and earth. The extreme differ- 
ence in depth of the water would be about 20 inches, or, sub- 
stituting the sun for the moon, it would be about 9 inches. 
If after the prolate form had been produced the disturb- 
ing bod>were to be suddenly annihilated, the ocean, sup- 
posing it covered the whole earth, would be thrown into 
a state of oscillation between a prolate and an oblate form. 
The time of the oscillations would depend on the depth of 
the water, and they would gradually die out from viscos- 
ity and other resistances. If the moon were to move 
round the water-covered earth on the equator, similar free 
oscillations would be set up and would gradually die out, 
but at the same time other motions would be forced and 
would not die out Supposing first, for the sake of simpli- 
city, that the effects of viscosity were very great, the wa- 
ter would be permanently raised all round the equator so 
as to increase the ellipticity of the surface of the sea, and 
such an effect, on a minute scale, is in fact produced. But, 
besides that, the equatorial section of the form of the 
water would be elliptical, the water continuing to pile up 
as long as it was at all drawn toward the moon; so that 
high tide would not be reached until 4 hours 45 minutes af- 
ter the moon had crossed the meridian. If the resistance 
is not so great the time of high tide will be earlier or later, 
according as the natural oscillations are quicker or slower 
than the forced motion. The resistance will also produce 
small component oscillations of periods one half and one 
third of those of the principal oscillations. Every in- 
equality in the motion of the sun and moon produces its 
own distinct component tide; but the magnitudes of the 
tides are very different from the magnitudes of the inequal- 
ities. The forms of the continents and of the sea-bottom 
affect the range of the tides in two ways. In the first place, 
they form basins in which the waters are susceptible of 
free stationary oscillations of various periods. Now, it is 
a known theorem of dynamics that forced vibrations at- 
tain large amplitudes when their periods are nearly the 
same as those of free vibrations, but are very small when 
their periods are nearly double those of free vibrations. 
In the second place, the continents in many cases force 
the ocean into canals, in which the tides take the form of 
progressive waves of translation, which will be greatly in- 
creased by a narrowing and still more by a shoaling of 
the channel in the direction of their progression. In this 
case there are distinct cotidal lines. In the North At- 
lantic the semidiurnal tide is large, but much larger in 
the eastern and northern parts than on the southern and 
western sides. The diurnal tides, on the other hand, are 
remarkably small. High tide occurs in the northern parts 
three or four hours earlier than in the southern ; and be- 
tween them, about Nantucket, there is little tide, and in 
many places four tides a day. In the Gulf of Mexico the 
semidiurnal tides are very small, and the diurnal tides are 
alone sensible. In a few places, as Tahiti, in the Pacific, 
and Courtown, in county Wexford, Ireland, the lunar tides 
almost disappear, so that high tide never occurs many 
hours from noon or midnight, and near such places there 
are others where the tides almost altogether vanish. 
The tide of the sea had filled the chanel of the riuer of 
Raman, llakluyl's Voyages, I. 10. 
A sea full of shelves and rocks, sands, gulfs, euripes and 
contrary tides. Burton, Anat. of Mel., p. 594. 
tide-gate 
7. Ebb and flow ; rise and fall ; flux and reflux. 
There is a tide in the affairs of men, 
Which, taken at the flood, leads on to fortune. 
Shak., J. C., Iv. 3. 218. 
8. Flow; current; stream; flood; torrent. 
What a tide of woes 
Comes rushing on this woeful land at once ! 
Shak., Rich. II., ii. 2. 88. 
An honest gentleman ; but he's never at leisure 
To be himself, he has such tides of business. 
B. Jonson, Devil is an Ass, v. 1. 
The usual daily clearance has been making in the city 
for an hour or more ; and the human tide is still rolling 
westward. Dickens, Dombey and Son, iv. 
Acceleration and retardation of the tides. See 
acceleration. Atmospheric tides. See atmospheric. 
Declinational tide. See dedinational. Lagging of 
the tides, see lagging. Lee or leeward tide. See lee- 
ward. Meteorological tide, a rise and fall of the sea 
due to regular alternations of the wind, to regular rain- 
fall and evaporation, or to any other meteorological in- 
fluence. Priming Of the tides. See lagging o/ the 
tides, under lagging. Retard Of the tide. See retard. 
To work double tides, to work night and day. See 
def. 5. 
Thus both that waste itself might work in vain 
Wrought double tides, and all was well again. 
Crabbe, Works, I. 52. 
Weather tide, a tide running to windward. 
tide 1 (tid), t'. ; pret. and pp. tided, ppr. tiding. 
[< ME. tiden (pret. tidde, pp. tided, tid), < AS. 
tidan, happen, < till, time, hour: see tide 1 , n. 
In the later senses from the modern noun.] I. 
intrans. If; To happen; betide. 
I dorst nan sworn, 
The sholde nevere han tyd so fayre a grace. 
Chaucer, Troilus, 1. 907. 
2. To drift with the tide; specifically (naut.), 
to work in or out of a harbor, etc., by taking 
advantage of the tide and anchoring when it 
becomes adverse. 
Here, because of the many shelfes, we were f orc'd to tyde 
it along the Channel!. Evelyn, Diary, Sept. 28, ltS41. 
Now it came to pass that on a flue sunny day the Com- 
pany's yacht the Half-Moon, having been on one of its 
stated visits to Fort Aurania, was quietly tiding it down 
the Hudson. Irving, Knickerbocker, p. 251. 
To tide on, to drift on ; continue ; last ; get on or along. 
I have given him relief, and he may tide on for some 
considerable time. Lancet, 1891, 1. 72. 
II. trans. 1. To drive with the tide or cur- 
rent. 
Their images, the relics of the wrack, 
Torn from the naked poop, are tided back 
By the wild waves, and rudely thrown ashore. 
Dryden, tr. of Persius's Satires, vi. 67. 
2. To carry through; manage. 
I will tide 
This affair for you ; give it freight and passage. 
B. Jonson, Staple of News, iv. 1. 
3. To succeed in surmounting: with over: as, 
to tide over a difficulty. 
tide 2 t. An obsolete preterit of tie 1 . 
tide 3 !. An erroneous Middle English form of 
tidy 1 . 
tide-ball (tid'bal), . A ball hoisted on a staff 
to indicate the height of the tide, 
tide-coacht (tid'koch), n. A stage-coach plying 
in connection with a packet whose arrival and 
departure depended on the tide. 
He took a place in the tide-coach from Rochester. 
Smollett, Roderick Random, xxiv. (Dames.) 
tide-crack (tld'krak), n. Same as tidal crack 
(which see, under tidal). 
tide-current (tid'kur'ent), n, A current in a 
channel caused by the alternation of the level 
of the water during the passage of the tide- 
wave. 
tided (ti'ded), a. \_< tide 1 + -ed^.] Affected by 
the tide; having a tide; tidal. 
The tided Thames. Bp. Han. 
tide-day (tid'da), n. The interval between 
two successive arrivals at the same place of 
the vertex of the tide-wave. 
tide-dial (tid'di"al), . See dial. 
tideful (tid'ful), a. [< tide 1 + -full Season- 
able ; opportune. [Obsolete or local.] 
tide-gage (tid'gaj), . 1. A graduated beam or 
spar serving to indicate the rise or fall of the 
tide: sometimes placed on shoals and bars. 
2. An apparatus for recording the movements 
of the level of water. A pencil is attached to a float 
by means of mechanism so as to move vertically with the 
level, but in diminished measure, the paper upon which 
the pencil marks being meanwhile carried horizontally 
at a uniform rate by means of clockwork. More compli- 
cated instruments perform integrations mechanically. 
tide-gate 1 (tid'gat), . [< tide 1 + gate 1 .] A 
gate through which water passes into a basin 
when the tide flows, and which is shut to retain 
the water from flowing back at the ebb. 
