Compensation Eye-pieces. for Apochromatic Objectives. ================================================= Eye-pieces | 4 | 6 | 8 | 12 | 18 --------------+------+------+------+------+------ Price $ |=6.50=|=6.50=| =10= | =10= | =8= ================================================= Compensation Eye-piece 6 with micrometer =$8.50= =Magnification= of the Apochromatic Objectives in combination with the Compensation Eye-pieces. ================================================== | Eye-pieces Objectives |-----+-----+-----+-----+----- | 4 | 6 | 8 | 12 | 18 --------------------+-----+-----+-----+-----+----- { 16 | 70 | 100 | 125 | 155 | 225 Dry Series { 8 | 140 | 200 | 260 | 325 | 465 { 4 | 300 | 430 | 550 | 675 |1000 --------------------+-----+-----+-----+-----+----- Oil-Immersion 2 | 575 | 820 |1080 |1500 |2250 ================================================== [Illustration: Double revolving Eye-piece.] Until very recently we have manufactured no arrangement for changing oculars on the microscope. This was due in part to the fact that there was no great demand for such an accessory and in part to the clumsiness of all those revolving eye-pieces which changed the entire ocular. The latter of these difficulties has been overcome in our present revolving eye-piece by such an adjustment of the collecting or lower lens of the eye-piece that it may remain permanently in position, the eye lens of the combination alone moving in the revolver. So accurate is the construction of the revolver and so carefully are the lenses adjusted that the eye-pieces may be changed while a specimen is in focus on the microscope stage without a readjustment of the focus. The revolving eye-piece is also particularly well adapted to use as a micrometer ocular, for when the eye lens is turned aside a micrometer scale may be inserted and rests upon the diaphragm of the eye-piece. Once adjusted in this way the micrometer values are the same for all the eye lenses of the combination. $ Prices: =Double revolving Eye-piece=, without eye lenses =4.--= Each eye lens =1.25= =Eye-piece Micrometer=, No. 86 =2.--= =Stands.=