262 
Transactions of the Society. 
is a Piece to fix to my Instrument, in order to slip it on to this Tube * 
it consists of a Hoop of Brass, with a Screw to make it embrace the 
Tube ; this Hoop is fasten’d on a Plate, in which is a Slit or Notch at 
A, the Nut of the Instrument d is to be loosen’d till the Plate will go 
underneath it ; then put the Screw B through the Socket F, at the End 
of the Sliding Bar represented in Plate I, Fig. l,,and fix it fast, the 
Instrument is then ready to slip on to the Ap^>aratus abovemention’d,. 
and by drawing the Head of the Instrument backwards or forwards 
you may adjust it immediately to any of the Magnifiers. . . . The 
properest Glasses to be used for this Purpose are the 2d and 3d.” 
Bibright (pi. V.). 
The next patent to which I would direct attention does not appear 
to have ever received notice from any of the later writers on the- 
Microscope. It is for a combined portable Microscope and Telescope ; 
the specification is No. 640,* bearing the dates of the 7th February 
and 30th May, 1749. The patent was granted to “ Thomas Bibright, 
of the Parish of Saint Lawrence Mildred, London, Optician,” for “ Air 
entirely New Method of Making Small Perspective Glasses, with 
Mathematical and other Instruments and Twees in one and the same- 
Case, both w T ith and without Miscrocopes or Magnifying Glasses, 
therein, in a very Portable, Neat, and Ornamental Manner, which, 
by reason of their Size, would be very Convenient and Usefull to His 
said Majestie’s [George II.] Subjects, and in Making of which Glasses 
a considerable Number of Opticians and other Handicraft Workmen 
would necessarily be Employed.” I would notice in passing that the 
spelling of the word miscrocope is evidently only a clerical error. 
As this Microscope has never received any attention, I subjoin the- 
following explanation of the instrument from the specification together 
with the figures referring to the same, as being worthy of the notice- 
of the Society : — 
“ The outside case, and the severall parts thereof, and the instru- 
ments or twees therein contained, are to be made of gold, silver,- brass,, 
steel, or any other metal, or the whole or part of the outside case mav 
be made or covered with shagreen, fish skin, or leather, with rims and 
hinges of gold, silver, or other metal, or may be sett or inlaid with 
pearl, jewels, or any sort of precious or curious stones. The Figure 
A, a , is the perspective glass as it is to be seen thro’, having both the 
sliders out or sett open. 1 is an eye glass, and 2 is an object glass. 
b, b, are the heads in which the said glasses are sett or fixed. C is the 
joynt or shutting of the case, which may be drawn out at pleasure 
to adjust it to the sight. The Figure Q is the same case with the 
object end open in its proper position when used for a miscrocope. 
The Figure B, B, represents the body of the said case without the 
top, which draws off at the said joynt or shutting C, showing the 
* Reprinted in 1856. 
