47. =The same stand= with prism-tube No. 49, for erected image; with objectives 2 and 3, magnifying 40 and 80 diam. =36.--= [Illustration: Dissecting microscope with erected image after R. Pfeiffer.] =The Dissecting microscope with erected image according to Prof. R. Pfeiffer= has been constructed in such a way that all parts extending on both sides can be folded or turned, so that the instrument fits in a very small case. The base consists of two parts which may be folded. The stage can be brought in a position vertical to the optical axis and the metal hand rests laid on top of the stage. They are connected with the latter by joints. The mirror can also be turned and put parallel to the pillar. A round glassplate is set in the stage, below which is an iris diaphragm to properly regulate the illumination. The adjustment is by rack and pinion. Two rightangle prisms are mounted inside the tube in such a manner that the image obtained by the objective is reflected into the eye-piece and appears erected. The eye-piece is of the Ramsden form. Three objectives of different magnifying power with specially long working-distances have been constructed Nos. 1, 2, 3. The following table shows the magnification of the objectives in connection with the eye-piece. Objective 1 2 3 Magnification 18 40 80 diam. Working distance 58 mm 18 mm 6 mm Prices: 48. Folding dissecting microscope, stand only =24.--= 49. Upper part of the microscope, consisting of tube with prisms, and one eye-piece =16.--= 50. Objectives 1, 2, 3, a $ 6,00 =18.--= --------- 51. Stand with complete outfit =58.--= The instrument is furnished in a mahogany case with nickelplated handle, lock and key. [Illustration: No. 52. No. 53. No. 54. Lens-holders.] 52. =Lens-holder= on iron foot with moveable arms, the joints of which may be fixed by thumb-screws, rack and pinion adjustment--without lens =7.20= 53. =Lens-holder=, nickel-plated stand with attachment of the collar holding the lens by ball and socket joint =4.--= 54. =Lens-holder= on heavy iron foot, ball and socket joints, adjustable to any position--without lens =3.25= 55. =Pocket microscope.= The size of an eye-piece, in box =3.25= 56. =Lens= for examining Algae =1.25= [Illustration: Dissecting Stage No. 57. With Lens No. 71.] 57. =Dissecting Stage= with white glass plate and moveable lens-holder--without lens =2.--= 58. The same with lens No. 71 =3.25=