Identifier: encyclopaediabri18edin (find matches)
Title: Encyclopædia britannica; or, A dictionary of arts, sciences, and miscellaneous literature
Year: 1810 (1810s)
Authors:
Subjects: Encyclopedias and dictionaries
Publisher: Edinburgh : A. Bell and C. Macfarquhar
Contributing Library: University of California Libraries
Digitizing Sponsor: Internet Archive

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raulic mean depth, we find the area S of the feftion bydividing the difcharge 1514169 by the velocity 27. Thisgives us 56080.368. Then we get the breadth B by the formula formerly given, B = /vf:^^)—2Sl + —^, =11802.296 inches, or 150.19 feet, and the depth /i=. ■3I.I 15 inches. With thefe dimenfions of tlie feflion vre are certainthat the channel will be permanent; and the cills ofthe flood-gate being all fixed agreeable to the primitiveflope, we need not fear that it will be changed in theintervals by the aflion of the current. The gates beingall open during the freflies, the bottom will be clearedof the whole depofited mud. ,,. We muft now ftation the flood-gates along the newsrationocharmel, at fuch diftances that we may have the depth tlif flooii-of ^^ aler wliich is proper for the lighter? that are to bcS»i *•employed ^__ HiVEKS. Plate CCCCLXIJ .-^,./. r^c J. 4_ , B ^ r ^ ^ « ^^HV^^ =N „■ \ ,13 D C ^ ^^ ~~—*j S B r,;- S x^y-7- X =^- ry.,., t>fV./2 4 - / 1^ G I
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Part II. Prnical emplo)ed in the navigalion. Suppofe this to be fourJiifcrences. fgjt. We niurt firft of all leam how higii the water■^ will -be kept in this new channel during the lummerdroiiu^hls. There remained in the primitive channelonly two feet, and the fcAiou in this cafe had 20 feeteight inches mean width ; and the difcharge correfpo.id-ing to this fcdion and flope of t/j^ is, by the theoremof uniform motion, 130,849 cubic inches per fecond.To find the depth of water in the new channel corre-fponding to this difcharge, sjnd the fame flope, we mufttake the method of approximation formerly exemplified,remembering that the difcharge D is 130849, and thebreadth B is 1760.8 at the bottom (the llant fides be-ing four thirds). Thefe data will produce a depth ofVater =^6j inches. To obtain four feet therefore be-hind any of the llood-gates, we muft have a fwell of 41^inches produced by the gate below. We muft noiv determine the width of paffage whichnjuit be given at the gencyclopaediabri18edin

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