68 



under ordinary manipulative operations, it should 

 not be required that the base be held with one 

 hand, while the other makes the adjustments. We 

 can imagine nothing more aggravating than a lack 

 of stability. A considerable weight directly under 

 the pillar is of little value, or a great expansion of 

 the resting points with extreme thinness is little 

 better. There should be a combination of both 

 qualities and if suitable proportions are not main- 

 tained, an excess can hardly be called a fault, 

 whereas too little would certainly be. 



A favorite and good method to obtain increased 

 weight within reasonable dimensions is, to load the 

 base with lead and while some dealers, from inter- 

 ested motives, point this out as a defect, a pur- 

 chaser need not hesitate on this account if the 

 instrument is in other respects acceptable. 



Joint for Inclination. - This should work 

 smoothly but firmly and the arm should remain in 

 any position in which it is placed. If it has a 

 gritty sensation, the two parts are liable to " eat ' 

 and finally reach a point where they cannot be 

 moved. 



Besides the above qualification a good joint 

 should work without the slightest back-lash, when 

 the arm is worked quickly back and forth over a 

 small space. 



When the arm comes against the stop for 

 upright position it should not lean forward. 



