28 NEW YORK STATE MUSEUM 



Where the strata are especially porous and where underground or 

 permanent ground water supplies are very extensive and where at 

 the same time the largest or deepest pressure tunnels are projected 

 some uneasiness has been entertained as to the extent of interference 

 from inflowing water during construction. An attempt to form 

 some idea of the ease of such underground circulation has been 

 made by a systematic pumping of one or two critical holes. The 

 results leave many factors still too obscure to draw definite con- 

 clusions. The test will be taken up again in the discussion of the 

 Rondout siphon in part 2. 



Laborator}- tests and experiments on materials complete the list 

 of lines of investigation with which this bulletin is concerned. 

 Although from the nature of the case these are elaborate and 

 unusually complete, the more important lines are not at all new. 

 All the methods of petrographic. chemical, and physical manipula- 

 tion that seem to promise practical results of value to the success 

 of the undertaking are followed and the data are organized and 

 interpreted and conclusions are formulated with as great deiinite- 

 ness for practical bearing as other lines of investigation. 



