16 On Uniformity of Nomenclature in regard to 
self-stultification. To call two lenses, of identical magnifying power, 
respectively ^th and ( yth inch lenses, is just as indefensible as to 
call two houses of equal height, 40 and 50 feet high respectively. 
To argue against the existing looseness of usage in naming lenses, 
is only to state what everybody knows in regard to the advantages 
of uniform standards of measurement generally. So impressed are 
many microscopists with the urgency of this question, and so deter- 
mined are they to escape from some of the present confusion, that a 
committee has been appointed to report on the subject. Though that 
committee is unprepared to report, it is believed that giving publi- 
city to some facts and opinions involved in the consideration, may 
lead to useful agitation and to increased definiteness of ideas and of 
information in regard to it. Of course it would be premature to 
claim or expect accuracy of statement or safety of opinion in such 
a complication of disputed questions ; and what is said, is designed 
to he contributory and suggestive, and in no degree dogmatic or 
final. 
The great variation in objectives of identical name is familiarly 
known and is undisputed. Among other people one-fourth of an 
inch is less than four-tenths and more than one-fifth ; but among 
microscopists it may often be more than the first or less than the 
last. An indefinite number of figures might be published to prove 
or illustrate this irregularity, the writer having been particularly 
interested in making and recording these comparisons for more 
than a dozen years, and Messrs. Bicknell, Biscoe, Higgins, Cross, 
and many others having been especially interested in the same 
study ; but it is idle to prove what everybody knows and admits. 
So familiar have some of these apparent errors become by use, and 
good usage too, that they have been often accepted as established, 
even one of the latest authorities * stating the power of the J-inch 
objective five times as high as that of the 1-inch. 
In the early days of the compound microscope as a really useful 
instrument, we find microscopists wishing that microscope makers 
would “ grind their glasses to some settled standard. ”t We are 
willing to be more reasonable now, or else the conditions stated 
have become more difficult. We do not desire, nor consider it 
practicable, that the opticians should make all their combinations 
of certain definite and conveniently-graded powers ; but we do pro- 
pose so to name our powers, if we can, that each number shall 
group together all those powers of which it is the nearest and best 
description. 
Makers would doubtless be considered as doing a favour to 
those who use their instruments if they would, after finishing 
lenses, carefully estimate their powers and name them by the frac- 
* Suffolk, ‘ Microscopical Manipulation.’ London, 1870. 
t Baker on Microscopes. London, 1742. 
