32 THE MICROSCOPE. 
The plan of my nose-piece is to have a collar or screw on each 
objective, armed with three equidistant, pins or lugs—though two or 
four would answer also, or still better, and what I hope will be the 
ultimate outcome of the plan, to have the objective made without 
society screw, but armed with the 3 pins itself and having the 
external diameter of 1 in. or 7% in. at least, since the society screw 
is confessedly too small. 
Then 2d, let the end of the microscope tube be furnished with 
3 slots just wide enough to receive the 3 pins on the objective and 
say % in. deep, the slots to be simple and straight, the body-tube to 
have also a raised ring or rim at the end to retain in place a revolv- 
ing ring. 
3d. A ring to fit over the end of the tube and to be retained 
in place as above described, and having three slots in it of the shape 
of an inverted L, and also a milled raised part by which it can be 
- revolved through about a ¥% revolution. This milled rim may be 
above or below or outside of the slotted portion of the ring, as the 
fancy of the maker may dictate. 
Preferably and ultimately this should be a permanent part 
of the microscope to the exclusion of the society screw, and objec- 
tives should be made to correspond with a few rings as described 
above, for adapting old objectives; but, of course, it can be made 
in the form of an adaptable-fitting with screw to fit in the end 
of the stands now in use. Now when the milled ring is turned so 
that the slots in it correspond to those in the inner tube the lugs on 
the objective slip up easily to the end, then a turn of say quarter of 
an inch of the ring clamps the -objective securely and very firmly. 
No amount of pulling or twisting at the objective can turn it or 
loosen it at all, while in ordinary “double nose-pieces” the slight- 
est touch sometimes pushes the objective far to one side of the 
optical axis, and with every other form of nose-piece now in use 
the use of the adjustment collar is liable to loosen the objective 
unless it is screwed in very firmly. Then, too, this nose-piece per- 
mits of the most instant interchange of objectives, no other form 
permitting of a more rapid substitution, and the number that may 
be so changed is unlimited Any one of your whole battery may be 
substituted for the lens now on the tube, while with the common 
double and triple nose-pieces this alteration is limited to one or two 
others only, and that one or two must be kept sticking out above 
the stage obstructing manipulation and liable to injury. 
