Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: no indication of an actually existing fact pertaining to the order of human mortality in the shape of a uniformity of nature. The average thus affords, in an individual result which can be readily pictured to the mind and retained in memory with facility, a general notion of a number of quantities, and provides us with the means of conveying the same notion to other minds without the necessity of presenting a lengthy list of the isolated quantities themselves from which, in their multiplicity, no lucid and definite conception could be constructed with ease. If, for example, we formed the average in the ordinary manner of the heights of 100 houses in a street, the result would not represent any real entity, any individual house, but would merely furnish a fictitious height expressing as nearly as possible the several altitudes of the individual buildings. An average accordingly fails to serve as a guide to the future based upon the experience of the past. A mean, on the other hand, it is rightly contended, does indicate an approximation to a definite existing quantity; and, applying language of a metaphorical character, points to some model or standard inherent in Nature, some real existence expressive of law or uniformity or intention, to which the various observations obtained by human measurement or induction refer, by the symmetric nature of their deviations, as the type to which they severally tend. A well-known illustration may be considered, but for its appreciation and a complete conception of this scientific and natural significance of a mean a brief explanation of a certain mode of measurement, to which the name of " Weights " is applied, requires attention,—" weights " consisting of numbers expressing the relative practical worth or value of observations. An ...