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# Title: Opticks: Or, A Treatise Of The Reflexions, Refractions, Inflexions and Colours Of Light (shelfmark Leibn. Marg. 193)
# Folio 9, page id 1677894601:0181
# Original at the GWLB: https://digitale-sammlungen.gwlb.de/resolve?id=1677894601&page=181
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# Model: FoNDUE-GD_v2_ft_Leibniz, run 74, 2026-09-06T16:05:13Z — 36 lines, status machine
# Lines: 36 recognised, mean confidence 0.88
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10
block Sxocappeared inthe middle ot the RinoSOFC olOuES
without any other presture than that ot the reisht ot
the Cilass. And no mealurins the Diameter ot the
tifch dark Cirele as accurate lr as l could, I Found it the
titth part ot an Ineh preciselr. This measure vras taken
rith the points ot a pair of Compasses on the upper sUI-
tace on the uipper CitlaIs, and my Liye ras about cieht
Or nine Tnches distance trom the Cilals, almost perpen-
dicularly over ic, and the Class Was? oF an Inck thick,
and thence ic is caly to collect that the true Diameter
Ot the Rins betrcen the Glasses Was greater than its
mealured Diameter abore the Classes in the proportion
et 80 t079 or thercabouts, and br consequence equal
co  PartS oF an Inch, and its true Semi-diameter equal
10  PartS. Nor a5 the Diameter oF the Sphere (182 In-
ches) is to the Semi-diameter of this htch darke Rins
EDaLES OF an Inch) (0 is this Semi-diameter to the
thickness oF the Air at this Ateh dark Ring; irhich is
ThereFOrC;  OF inasa PaNtS oF an Inch, and the ftch
1c
parE ThCTCOF; viZ. ThC aBth part oF an Tuch, is che
thicknels oF the AIr at the RPK OF these dark RInOS.
The same Experiment lrepeated rith another dou-
ble conrex Object- glass ground on both sdes to one and
the Came Sphere. IES Focus was distant From it 168
Inches, and cheretore the Diameter ot chat Sphere Wras
184 Tnches. This Glass beine laid uxon the lame
plain Gla(S, the Diameter OF the AEEH oF the dark
Rinss, Wrhen the black Spot in their center appeared
plainty without pressins the Glasses, as by the mea-
lure ot the Compasses upon the upper Cila(s s parts
ot an Inch, and by consequence betireen the Gilasles it
23
Va5  FOr the upper CilaIS ass ot an lnch thick,
and