DAMON.] VIRGINIA. 171 
About three years ago an allotment was made for a new well at Fort 
Monroe, and I was consulted by Lieutenant-Colonel Hains, of the 
United States Engineer Corps, in regard to its prospects. I predicted 
that basal Potomac water would probably be found between 1,300 and 
1,350 feet, and that its amount and quality would be satisfactory. 
Owing to some official causes, the boring has not as yet been com- 
menced, and I do not know the plans of the War Department regarding 
it. A well to the granite bedrock at Fort Monroe would throw much- 
needed light on the underground geology of southeastern Virginia 
and would probably afford a complete basis for water predictions over 
a wide area of that region. 
North End Point, Back River. — This well is about 6 miles north- 
northeast of Fort Monroe, and was bored in 1880-87 to a depth of 1,172 
feet. It did not yield a supply of water, owing, I believe, to insufficient 
depth, if not also to improper management. It is asserted to have 
reached granite, but no sample was obtained, and the nature of the 
rock was only surmised from its hardness. The record of this well, 
kindly furnished to me by Mr. C. C. Knox, of Norfolk, is as follows: 
Feet. 
0-75 white sand and gravel. 
75-80 blue clay. 
80-100 white sand. 
100-130 thin layers of sand and blue clay. 
130-155 blue or gray sand. 
155-165 quicksand. 
165-170 hard white sand. 
170-185 loose white sand. 
185-187 black marl. 
187-249 white sand and marl. 
249-250 rock. 
250-267 blue clay. 
267-268 stone. 
268-275 hard sand. 
275-530 blue clay with thin marl layers. 
530-600 hard blue clay . 
600-618 quicksand. 
618-620 stone or bowlder. 
620-625 white sand. 
625-626 yellow sand. 
626-695 clay and sand mixed. 
695-696 gravel and clay. 
696-740 hard and soft layers of blue clay. 
740-748 very hard clay. 
748-913 soft blue clay. 
913- 920 hard blue clay. 
920-926 coarse sand . 
926-939 sandstone. 
939-955 hard sandstone. 
955-973 hard sand with few gravels. 
973-1,000 hard sandstone. 
1.000-1,007 sandstone with two veins of gravel and some water. 
