., o 



= 3 



No. 46. *Attachable Mechanical Stage (old pattern). Fig. 15. 



The construction of this stage is based in its essential features upon the 

 principle evolved by Mr. J. MAYALL junr. (see Journal Roy. Microsc. Soc. (2), 

 V, 122, 1885). Two sliding pieces, mounted at right angles to, and in immediate 

 contact with, one another, are moved by means of two milled-heads. Their 

 various positions are recorded by scales and verniers. The range of the lateral 

 movement is 50 mm (2 in.), that of the movement from front to rear 30 mm 

 (l 3 / lti in.). The apparatus may also be used as a "finder" (see directions for 

 using this accessory). 



No. 47. *Attachable Mechanical Stage (new model), Fig. 16. 



The milled-heads which cause the movement of the sliding pieces are 

 co-axial in this pattern of traversing stage and retain their relative posi- 

 tions in turning. The lateral movement may be effected with 

 either the right or left hand. 



The margin of movement is slightly greater than with the small mechanical 

 stage, No. 46; the area which can be effectively searched measures about 

 60 X 30 mm (about 2 3 / 8 X ! 3 /i6 in.). 



The peculiar mechanism of this stage guarantees a considerably 

 greater security in the movement of the sliding pieces and 

 fulfils all requirements of a movable stage when applied to the 

 purposes of a "finder". 



An accurately gauged centring-glass, upon which the divisions of the 

 crossed line are marked from two edges of the slide, is Jsupplied with each 

 stage No. 47. (See Zeitschr. f. Instr.-Kde., vol. XX, 1900, pp. 325327 see also 

 the directions for using the stage.) 



The Attachable Mechanical Stages Nos. 46 and 47 are attached to the 

 prism flange of the Stand: they are designed for use on our Stands IV A C and 

 V A C Only and can be attached to these Stands without any special adaptation. 



