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valley. In the excavations for the foundation of the second dam of the 

 Bloomington water-works, a joint, widely opened by solution, was trace(^l 

 down seventeen feet into the rock, without closing up. Some of these 

 vreathered joints are illustrated in the accompanying photographs (Figs. 

 (> and 7), and other illustrations may be found in the papers of the 

 wi'iter and Dr. Beede, cited above. 



Fig. 7. A quarry ace in the Hunter vallej- region, Bloomington, showing joints widely opened 

 by solution. 



The valley sitles in the limestone area are apt to bo so leaky as to 

 render them totally unfit to act as i*etainers of impounded water. This 

 has been very thoroughly demonstrated in the case of the Bloomington 

 water-works plant. The original dam at this plant has long been decrepit, 

 and the extensive leakage is due to a variety of causes, among which the 

 chief is probably faulty construction. A considerable quantity of water, 

 however, finds its way into the joints and bedding planes of the rock, under 

 the spillway (Fig. 5), and is recovered by the second pond, which is 

 immediately below the firs^t. In the case of the second pond, built in 



