But because these, though exceeding easily
made, are yet very troublesome to be us'd, because of their smallness,
and the nearness of the Object; therefore to prevent both these, and
yet have only two Refractions, I provided me a Tube of Brass, shap'd
much like that in the fourth Figure of the first _Scheme_; into the
smaller end of this I fixt with Wax a good _plano convex_ Object Glass,
with the convex side towards the Object, and into the bigger end I fixt
also with wax a pretty large plano _Convex_ Glass, with the _convex_
side towards my eye, then by means of the small hole by the side, I
fill'd the intermediate space between these two Glasses with very clear
Water, and with a Screw stopp'd it in; then putting on a Cell for the
Eye, I could perceive an Object more bright then I could when the
intermediate space was only fill'd with Air, but this, for other
inconveniences, I made but little use of.
My way for fixing both the Glass and Object to the Pedestal most
conveniently was thus: Upon one side of a round Pedestal AB, in the
sixth Figure of the first _Scheme_, was fixt a small Pillar CC, on this
was fitted a small Iron Arm D, which could be mov'd up and down, and
fixt in any part of the Pillar, by means of a small Screw E; on the end
of this Arm was a small Ball fitted into a kind of socket F, made in
the side of the Brass Ring G, through which the small end of the Tube
was screw'd; by means of which contrivance I could place and fix the
Tube in what posture I desir'd (which for many Observations was
exceeding necessary) and adjusten it most exactly to any Object.
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