accedence (aksedens)

time of the actual occurrence of high water at any place and what its time would be if it eccurred after the lapse of a uniform mean interval. In spring and neap tides the the former case the solar and lunar tides are synchronous, while in the latter the time of actual or lunar low water and that of solar high water are the same. But in the first and third quarters of the moon there is acceleration or priming of high water, as the solar wave is to the west of the lunar; and in the second and fourth quarters there is retardation or lagging, for an analogous reason. - Diurnal acceleration of the fixed stars, the exce of the apparent diurnal motion of the stars over that of the sun, arising from the fact that the sun's apparent yearly motion takes place in a direction contrary to that of its apparent daily motion. The stars thus seem each day to anticipate the sun by nearly 3 minutes and 56 seconds of mean time. accelerative acceler (ak-sel'e-ra-tiv), a. [ accelerate + -ive .] Tending to accelerate; adding to ve quickening progre ion. accelerator (ak-sel'e-ra-tor), n. [NL., etc., accelerate .] One who or that which accelerates; a hastener. Hence-( a ) In England, a post office van. (b) In an at ., a muscle, the accelerator urine, which expedites the discharge of urine. (c) In photog .: (1) Any substance or device which shortens the time of exposure of a sensitized plate or paper to the light, in either the camera or the printing-frame. (2) Any chemical which may be added to the developing solution to shorten the time nece ary for development, or, by increas accelerator ing the normal efficiency of the developer, to le en the requisite time of exposure. (d) An accelerating gun. See accelerate.