192 THE MICROSCOPE. 



out a traversing stage " Maltwood's finder " will be 

 found an efficient substitute. It consists of a glass 

 slide, 3 x 1^ inches, on which is photographed a scale 

 occupying a square inch ; this is divided by horizontal 

 and vertical lines into 2,500 squares, each of which 

 contains two numbers marking its " latitude," or place 

 in the vertical series, and its " longitude," or place in 



FIG, 127. -Dipping-tubes. FIG. 127a. Stock-bottle. 



the horizontal series. The scale is in each instance an 

 exact distance from the bottom and left-hand end of 

 the glass slide ; and the slide when in use should rest 

 upon the ledge of the stage of the microscope, and be 

 made to abut against a stop, a simple pin, about an 

 inch and a half from the centre of the stage. Messrs. 

 Beck supply this finder with their microscopes. 



Dipping-tubes are tubes of glass (tig. 127) about nine 



