Encyclopaedia; or, A dictionary of arts, sciences, and miscellaneous literature; constructed on a plan, by which the different sciences and arts are digested into the form of distinct treatises of . view rtmotc cbjef^s, and thatit is contrafled while we are viewing thie that arenear; and this he proved by experiment, and illuftraiedby figures. Scheiner alfo took a good deal of pains to afcer-tain the denfity and refractive power of all the humoursof the eye, by comparing their magnifying power withthat of water or glals in the fame form and circum-ftaTTres~^.inie7relult of his inquir
Encyclopaedia; or, A dictionary of arts, sciences, and miscellaneous literature; constructed on a plan, by which the different sciences and arts are digested into the form of distinct treatises of . view rtmotc cbjef^s, and thatit is contrafled while we are viewing thie that arenear; and this he proved by experiment, and illuftraiedby figures. Scheiner alfo took a good deal of pains to afcer-tain the denfity and refractive power of all the humoursof the eye, by comparing their magnifying power withthat of water or glals in the fame form and circum-ftaTTres~^.inie7relult of his inquiries was, that theaqueou5 humcur doth not differ much from water inthis relpeft, nor the cryftalline from glafs ; and thatthe vitreous humour is a medium between both. Healio very accurately and minutely traces the progrefsof the rays of light through all tjie humours ef theeye ; and after difcufllng every pofljble hypothefis con-cerning the proper feat of vifion, he demonftrates thatit is the tetina, and Ihows that this was the opinionof Alhazen, Vhellio, Kepler, and all the He produces many reatbns of hisown tor this hypothefis ; aniwers a great number of objeclicns /. Hiflory O I s. ohjcfUoD! :? ( to it: anJ, by ;i variety of arguments, re-futes the o]Mnion of ionncr times, that the ieat of vi-?jx ficn is in the Defcartcs makes a good number of ohfervaticns onof >•?- the phenomena of vifion. He explains fatisfailorilycartcj. (]j„ natural methods of judgin;^ of the magultudcr,, f;-tuations, and diftances, of oiijeiSts by the direflion ofthe optic axes; comparing it to a blind mans judg-ing of the lize and diftance of anobjcift, by feeling atit with two flicks of a knov^^n length, when the handsin which he holds them are at a known diftance tromeach other. He alfo obferves, that having been ac-cuitomed to judge of the fituation of objefts by theirimages falling on a jiarticular part of the eye ; if byany dillortion o
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Keywords: ., bookcentury1700, bookdecade1790, bookidencyclopaedi, bookyear1798
