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Information on Microscope Nosepieces.
Microscope Nosepieces
The nosepiece (S) of a microscope is the lower end of the body (M) provided with a screw for attaching object glasses. A revolving nosepiece is an appliance which screws into the nosepiece and which carries a revolving plate into which two or three object glasses can be fixed, known as double or triple nosepieces respectively. By rotating the revolving plate each object glass can be rapidly brought into use, being held in the tight Triple Nosepiece. Correct position by a spring clip . The best form is made so that no dust can drop into the back of the object glasses and they can be safely left attached to the microscope. The extra length of the body caused by the length of a nosepiece is 15 mm., and the drawtube should be closed by that amount or set at 145 mm. Instead of 160 mm. An object glass changer is an apparatus for rapidly changing glasses by another method. Each object glass is screwed into a fitting which slips into an adapter that is fixed to the nosepiece of the microscope, and as each fitting is provided with two adjustable abutment screws the object glasses can be fndividually adjusted so that they exactly register as regards the position of the field of view. Changing an object glass by this means is nearly as rapid and more accurate than that of a revolving nosepiece, and is far more convenient when the object glasses are to be used on different instruments or where more than three are used. It consists of an adapter which has on one side a sloping projection (A), and on the other a clamp screw (B) which actuates a bevelled nut (C). The adapter is clamped to the nosepiece of the microscope by a screwed ring (D), which is provided with slots, into which a halfpenny will fit for tightening it up. Loose fittings are supplied, one of which is screwed on to each object glass. Each fitting has a bevelled gap which fits loosely over the bevelled nut (C) of the adapter and swings round into position when a turn of the milled head (B) forces the fitting against the sloping projection (A) and holds it firmly in position. Each adapter has screwed studs with clamping screws, which form the stops in both directions when the object glass is in the correct position. These can be adjusted by means of a spanner supplied for the purpose, so that each lens can be centred with an accuracy that is never possible with a revolving nosepiece, because the error of each individual object glass cannot be compensated with the latter. The construction of this apparatus is so simple and rigid, having no slides to wear loose, that it remains in adjustment permanently. A box is supplied to carry object glasses with fittings screwed on ready for use, held against dust-tight pads.
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Microscope Equipment 
