REF 



REG 



which is 714 fathoms, he allows only 44" 

 of terrestrial refraction, so many being 

 contained in the 714 fathoms. See his 

 Memoir concerning- the trigonometrical 

 operations, 8cc. Again, M. de Lambre, 

 an ingenious French astronomer, makes 

 the quantity of the terrestrial refraction 

 to be the eleventh part of the arch of dis- 

 tance. But the English measurers, Col. 

 Edward Williams, Capt. Mudge, and Mr. 

 Dalby, from a multitude of exact obser- 

 vations made by them, determine the 

 quantity of the medium refraction to be 

 the twelfth part of the said distance. The 

 quantity of this refraction, however, is 

 found to vary considerably, with the dif- 

 ferent states of the weather and atmo- 

 sphere, from the fifteenth part of the dis- 

 tance to the ninth part of the same, the 

 medium of which is the twelfth part, as 

 above mentioned. Some whimsical ef- 

 fects of this refraction are also related, 

 arising from peculiar situations and cir- 

 cumstances. Thus, it is said, any person 

 standing by the side of the river Thames, 

 at Greenwich, when it is high water 

 there, he can see the cattle grazing on 

 the Isle of Dogs, which is the marshy 

 meadow on the other side of the river at 

 that place ; but when it is low water 

 there, he cannot see any thing of them, 

 as they are hid from his view by the land 

 wall or bank on the other side, which is 

 raised higher than the marsh, to keep out 

 the waters of the river. This curious ef- 

 fect is probably owing to the moist and 

 dense vapours, just above and rising from 

 the surface of the water, being raised 

 higher or lifted up with the surface of the 

 water at the time of high tide, through 

 which the rays pass, and are the more re- 

 fracted. 



REFRACTION, in gene'ral, is the devia- 

 tion of a moving body from its direct 

 course, occasioned by the different den- 

 sity of the medium it moves in ; or it is a 

 change of direction, occasioned by a bo- 

 dy's falling obliquely out of one medium 

 into another of a different density. The 

 great law of refraction, which holds in all 

 bodies, and all mediums, is, that a body, 

 passing obliquely out of one medium into 

 another wherein it meets with less resist- 

 ance, is refracted or turned towards the 

 perpendicular ; and, on the contrary, in 

 passing out of one medium into another 

 wherein the resistance is greater, it is re- 

 fracted or turned from the perpendicu- 

 lar. Hence the rays of light, falling out 

 of air into water, are refracted towards 

 the perpendicular ; whereas a ball thrown 

 into the water, is refracted from it. Now 

 the reason of this difference is, that wa- 



ter, which resists the motion of light less 

 than air, resists that of the ball more ; or, 

 to speak rrfore justly, because water, by- 

 its greater attraction, accelerates the mo- 

 tion of the rays of light more than air 

 does. See OPTICS. 



REFRACTION in island crystal. There is 

 a double refraction in this substance, con- 

 trary ways, whereby not only oblique rays 

 are divided into two, and refracted into 

 opposite parts, but even perpendicular 

 rays, and one half of them refracted. 



REGALIA, in law, the royal rights of 

 a King, which, according to civilians, are 

 six ; power of judicature ; power of life 

 and death ; power of war and peace ; 

 goods without owner, as waifs, strays, 

 &c. ; assessments ; and minting of mo- 

 ney. 



REGIMEN, in grammar, that part of 

 syntax, or construction, which regulates 

 the dependency of words, and the altera- 

 tions which one occasions in another. 



REGIMENT, in war, is a body of men, 

 either horse or foot, commanded by a co- 

 lonel. Each regiment of foot is divided 

 into companies, but the number of com- 

 panies is not always alike, though our re- 

 giments generally consist of ten compa- 

 nies, one on the right of grenadiers, and 

 another on the left of light troops. Regi- 

 ments of horse most commonly consist of 

 six troops, but some have nine. Regi- 

 ments of dragoons, in time of war, are 

 generally composed of eight troops, and 

 in time of peace, of six. Each regiment 

 has a chaplain and a surgeon. See TROOP 

 and COMPANY. Some German regiments 

 consist of 2000 foot, and the regiments 

 of Picardy, in the old French service, 

 consisted of 120 companies, or 6000 men. 



REGISTER, a public book, in which is 

 entered and recorded memoirs, acts, and 

 minutes, to be had recourse to occasional- 

 ly, for knowing and proving matters of 

 fact. Of these there are several kinds ^ 

 as, 1. Registers of deeds in Yorkshire and 

 Middlesex, in which are registered all 

 deeds, conveyances, wills, &c. that afiect 

 any lands or tenements in those counties, 

 w r hich are otherwise void against any sub- 

 sequent purchasers, or mortgagees, &c. ; 

 but this does not extend to any copyhold 

 estate, nor to leases at a rack-rent, or 

 where they do not exceed twenty-one 

 years. The registered memorials must 

 be engrossed on parchment, under the 

 hand and seal of some of the grantors or 

 grantees, attested by witnesses who arc 

 to prove the signing or sealing of them, 

 and the execution of the deed. But these 

 registers, which are confined to two coun- 

 ties, are in Scotland general, by which 



