i8;7-J 
Notices of Books. 
manner in which the pros and cons are placed before the reader. 
But we claim more for it than this : we think the author has 
treated the subject in an eminently suggestive and often original 
manner, and we cordially recommend the book not only to the 
rapidly-increasing list of members of the Aeronautical Society, 
but to all readers interested in a subject which has puzzled man- 
kind since the time of Daedalus. 
A Classified English Vocabulary , being an attempt to facilitate a 
Knowledge of Words and their Meanings by an Arrange- 
ment °f Ideas according to their Scientific Connection. 
London : Provost and Co. 
Th is little book is absolutely anonymous, not bearing on its 
title-page even a nom de plume. From the Preface we gather 
that the fundamental conception of the work first suggested 
itself to the author whilst attending a ledure on Mnemonics, in 
which was illustrated the singular facility with which a long 
string of names could be remembered when every name was 
linked to the name which followed it by some observed connec- 
tion between the ideas conveyed by them. We further learn 
that the construction of the classification adopted has been 
“ very much facilitated by the guidance derived from the classi- 
fication of ideas comprised in Dr. Roget’s ‘ Thesaurus.’ ” 
In attempting to form a conclusion on the merits of the 
treatise, a distinction must be drawn between the value of the 
author’s fundamental conception and the manner in which it has 
been here carried out. We fully grant that not merely in daily 
life, but in public speaking, and even in writing, there is a great 
■—and we fear an increasing — vagueness in the use of terms. 
Men do in faCt “ conned with the name no precise knowledge of 
the things, but apply it rightly or wrongly to every objed which 
seems to possess this undefined sort of resemblance to various 
other things called by it.” To give a familiar instance — Does 
not all England outside of stridly scientific circles persist in 
calling the cockroach a “ black beetle,” although it is no beetle 
at all, but a congener of the locust and the cricket ? And, on 
the other hand, do not our American cousins call the new insect- 
scourge which is travelling eastwards from Colorado, and which 
is a true beetle, the “ potato-bug ?” 
We fully agree with the author that such vague uses of lan- 
guage are a serious evil, and that any person by giving way to 
it tends to form “ defedive habits of observation ” and a general 
looseness of thought. 
But having admitted so much, the question remains — What is 
the remedy for this vagueness ? On this point let us hear what 
YOL. VII. (N.S.) I 
