NOTES ON THE GEOLOGY OF THE BAHAMAS 35 



was two feet in depth, and then suddenly deepened to eighteen feet over 

 a projecting ledge. Sounding across the hole did not show a greater 

 depth. The bottom of the hole was of soft coral mud. The bottom 

 of the creek surrounding the hole was covered with about two feet of 

 water, and in some places gradually sloped into the hole. Still farther 

 up the creek another hole was seen, but was not examined. The most 

 remarkable ocean hole that I saw was one near Grassy Creek, near 

 the southern end of the east side of Andros. The diameter was about 

 one hundred and fifty feet, and the shore itself formed one edge of the 

 hole. The sides were of sand at its angle of repose for a depth of about 

 six or seven feet below, and resting on an overhanging ledge of rock. 

 Where the tide had fallen it left the hole surrounded by at least a quar- 

 ter mile of sand flat on the ocean side, while, as stated above, the shore 

 formed the rest of the boundary. This hole I sounded with all the 

 line I possessed, but at twenty fathoms the weight was cut off, and I was 

 unable to obtain another to continue the sounding. The captain of 

 our boat, a reliable man, told me that in the "Pine-yard" was a hole 

 similar to this one, in which he had found no bottom with a line over 

 thirty fathoms in length. Before attempting to explain the formation 

 of these ocean holes it will be well to describe what the natives call 



Boiling Holes 



The first of these I was shown on Andros in a small creek that runs 

 into Conch Sound. The top of the hole was about a foot under water 

 at low tide, and close to the mangroves that formed the side of the creek. 

 It was about seven feet in length and about two or three wide. Below 

 the diameter increased, forming an overhanging ledge. When the tide 

 was low in the creek, but rising outside, the clear sea-water could be 

 distinctly seen ascending, thus producing the same appearance as 

 that presented by a mixture of sulphuric acid and water. Suspended 

 particles could also be seen rising. 



While sailing past Rat Cay, near Mastic Point, another "boiling 

 hole" was seen that was apparently about ten feet in diameter, and 

 from a distance we could see a perceptible "boil" on the surface that 

 was undoubtedly caused by the rising water. Our captain said that 

 when the tide was falling, the water in the hole went "down and 

 round" — which statement I believe, as the water was rising with some 



