RET 



RET 



In Saturn it is about 378 clays ; 



.Jupiter 408 



Mars 780 



Venus 585 



Mercury 115 



RETROMINGEXTS, in natural his- 

 tory, a class or division of animals, whose 

 characteristic it is that they stale, or 

 make water, backwards, both male and 

 female. 



RETURN, is most commonly used for 

 the return of writs, which is the certifi- 

 cate of the Sheriff, made to the court of 

 what he has done, touching 1 the execu- 

 tion of any writ directed to him; and 

 where a writ is executed, or the defen- 

 dant cannot be found, or the like, this 

 fact is indorsed on the writ by the officer, 

 and delivered into the court whence the 

 writ issued, at the day of the return 

 thereof, in order to be filed. 



RETURNING stroke, in electricity, is 

 an expression used by Lord Mahon, (now 

 Earl Stanhope), to denote the effect 

 produced bv the return of the electric 

 fluid into a body, from which, under 

 certain circumstances, it has been ex- 

 pelled. 



To understand properly the meaning 

 of these terms, it must be premised, that 

 according to the author's experiments, 

 an insulated smooth body, immcrged 

 within the electrical atmosphere, 'but 

 beyond the striking distance of another 

 body, charged positively, is at the same 

 time in a state of threefold electricity. 

 The end next to the charged body ac- 

 quires negative electricity ; the further 

 end is positively electrified; while a cer- 

 tain part of the body, somewhere between 

 its two extremes, is in a natural, unelec- 

 trified, or neutral state ; so that the two 

 contrary electricities balance each other. 

 It may further be added, that if the body 

 be not insulated, but have a communica- 

 tion with the earth, the whole of it will 

 be in a negative state. Suppose, then, a 

 brass ball, which may be called A, to be 

 constantly placed at the striking distance 

 of a prime conductor, so that the conduc- 

 tor, the instant when it becomes fully 

 charged, explodes into it. Let another 

 large or second conductor be suspended 

 in a perfectly insulated state, further from 

 the prime conductor than the striking 

 distance, but within its electrical atmo- 

 sphere : let a person, standing on an insu- 

 lated stool, touch this second conductor 

 very lightly with a finger of his right 

 hand; while with a finger of his left hand 

 he communicates with the earth, by 



touching very lightly a second brass ball, 

 fixed at the top of a metallic stand, on 

 the floor, which may be called B. Now, 

 while the prime conductor is receiving- 

 its electricity, sparks pass (at least if the 

 distance between the two conductors is 

 not too great) from the second conduc- 

 tor to the right hand of the insulated per- 

 son ; while similar and simultaneous sparks 

 pass out from the finger of his left hand 

 into the second metallic ball, B, commu- 

 nicating with the earth. At length, how- 

 ever, the prime conductor, having ac- 

 quired its full charge, suddenly strikes 

 into the ball, A, of the first metallic 

 stand, placed for that purpose at the 

 striking distance. The explosion being 

 made, and the prime conductor suddenly 

 robbed of its elastic atmosphere, its pres- 

 sure or action on the second conductor, 

 and on the insulated person, as suddenly 

 ceases, and the latter instantly feels a 

 smart returning stroke, though he has no 

 direct or visible communication (except 

 by the floor) with either of the two bo- 

 dies, and is placed at the distance of five 

 or six feet from both of them. This re- 

 turning stroke is evidently occasioned by 

 the sudden re-entrance of the electric 

 fire, naturally belonging to his bodv anil 

 to the second conductor, which had be- 

 fore been expelled from them by the ac- 

 tion of the charged prime conductor upon 

 them ; and which returns 1o its former 

 place in the instant when that action or 

 elastic pressure ceases. AY hen the se- 

 cond conductor and the insulated person 

 are placed in the densest part of the elec- 

 trical atmosphere of the prime conduc- 

 tor, or just beyond the striking distance, 

 the effects are still more considerable ; 

 the returning stroke being extremely se- 

 vere and pungent, and appearing consi- 

 derably sharper than even the main 

 stroke itself received direptly from the 

 prime conductor. Lord Mahon observes., 

 that persons and animals may he destroy- 

 ed, and particular parts of buildings may 

 be much damaged, by an electrical re- 

 turning stroke, occasioned even by some 

 very distant explosion from a thunder 

 cloud; possibly at the distance of a mite 

 or more. It is certainly not difficult to 

 conceive, that a charged extensive thun- 

 der cloud must be productive of effects 

 similar to those produced by the prime 

 conductor ; but perhaps the effects are 

 not so great, nor the danger so terrible, 

 as it seems to have been apprehended. It 

 the quantity of electric fluid naturally con- 

 tained, for example, in the body of a man, 

 were immense or indefinite, then the es 



