88 Geological Faults. [February, 
and artistically cultivated might have a very beneficial influ- 
ence in the development of the decorative arts. 
I cannot help mentioning an unfortunate error, clerical or 
typographical, in Mr. Wardle’s pamphlet. In the scheme 
showing the position of the silk-moths in the animal king- 
dom, “ arthropoda ” has been converted into “ anthropoda.” 
VI. THE “MYSTERY” OF GEOLOGICAL FAULTS. 
By Robert Ward. 
t N the January number of the “Journal of Science” 
D. Y. C. says that “ Faults are one of the mysteries 
of Geology,” and he asks, “ Why are faults so often 
found V-shaped ? How has such a phenomenon occurred ?” 
He further observes that “ Faults are not wholly owing to 
distridt subsidence, or more remotely to shrinkage. ... It 
is demonstrable that faults of the same district are not all 
of the same period. The new formations are found lying 
unconformably on older formations, each with their separate 
set of faults. And probably under these again would be 
other sets. I am strongly inclined, therefore, to believe it 
to be owing to causes ending finally in local compression, or 
yielding fluctuations of strata — waves, in a rough sense, of 
semi-fluidified strata.” 
The mystery will be easily solved if we admit that the 
Earth is a growing body. Faults take a V- shape when two 
cracks “ hade ” into each other in reverse directions, and 
the V-shaped mass of strata between the cracks is often 
thrown down as the result of a slow separation of the sides 
consequent upon the Earth’s expansion. For the same 
reason, whenever the strata on the two sides of an inclined 
crack are found at different elevations, the inclination (or 
hade) will always take a direction indicative of a separa- 
tion of the two sides. Perhaps, in some cases, this may be 
supposed to be accounted for by elevation alone, but cer- 
tainly it is best explained on the theory that the Earth is a 
growing body, and that the crack has widened so as to 
permit of the strata on one side being “ thrown down ” as 
