THE DUMPY LEVEL 





Fig. 8 



HIS model was introduced in England in 1845 by Wm. 

 CJavatt, C. E. , and is now in use in that country to 

 the exclusion of nearly all other types. The object- 

 ion to this type heretofore has grown out of the fact 

 that collimation has been made subservient to other 

 requirements; but we have found that it may be nearly 

 as readily tested and even more accurately secured. 



When the collars of a Y-level have not been per- 

 fectly made, or wear eccentric, or conical, in wye 

 bearings that are unprotected against dust, a state of affairs exists, so 

 far as adjustments are concerned, in which the Y-level offers little or 

 no advantage; and the dumpy level lays claim to superiority in that 

 there are fewer mechanical details in its construction which may 

 have any effect upon the character of the results obtained. 



In the Y-level the colli mated line of sight can be brought 

 exactly at right angles with the spindle through the height-adjust- 

 ment in the wyes; but in the dumpy, no authority has yet claimed 

 that this is necessary within a close approximation. * 



dumpifs ha. -..- ned with a cross bar and ht>o rigid upright 



supports. Some makers have af so gone to tin- t\t^me of making: the uprights 

 adjustable in height AM/ tliis impairs rigidity and adds unnecessary weight. 



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