Page:Popular Science Monthly Volume 11.djvu/591

Rh of a second, the time required in ordinary cases for the remaining act of willing was easily calculated to be about one twenty-eighth of a second. If these investigations can be regarded as entirely trustworthy, they tend to show that the mind perceives somewhat more slowly than it wills.

Of the personal equation, in its widest sense, there are many examples even more suggestive and worthy of extended treatment than these which have received mathematical measurement. These examples are to be found in all human action, and in the result of all human work. Noticeably is this true in all acts and occupations which have their basis and lowest forms in acts of imitation. None the less is it true in those higher forms of art and action where close imitation is less desired than the interpretation of some pervading spirit, or the representation of some underlying essential. In the acts of painting a landscape, of copying a picture, of interpreting a symphony, of reading a poem, of acting a play, of following an argument, or in any of the common or artistic acts of men, be they mental or physical, the personal equation of the actor enters as a perceptible element in the result. The discussion of the nature and value of the personal equation where it appears in forms so subtile as in the cases last mentioned would furnish many considerations of interest and instruction, but to undertake the treatment of these forms is beyond our present purpose or opportunity.



N the work by the late J. W. Foster, LL.D., on the "Prehistoric Races of the United States of America," published in 1873, when treating of the pottery of the mound-builders, on page 248, he says:

"On the Saline River, Gallatin County, Illinois, according to MS. notes of Prof. Cox, there is, just above low-water mark, a salt-spring, which was resorted to in the earliest settlement of the country, by those of European descent, for the purpose of procuring salt by evaporating the brine. Here occur, however, numerous fragments of pottery, showing that a prehistoric people had resorted to the same spring, and for the same purpose. From the slight curvature of the fragments it is evident that the vessels were of large capacity. The material is coarse, and the general thickness of the vessel is about half an inch, but at the rim it is three-quarters of an inch. The exterior is marked by vertical lines of depression about half an inch apart, with bars less conspicuous and close together, sometimes at right angles, and at others oblique. When I first saw these specimens, I was somewhat surprised that the makers should bestow so much ornamentation on vessels so coarsely made, and applied to such ordinary uses;