The Presidents Address. 
141 
ber of our members, which now amounts to 267, being 26 
more than at the corresponding period of last year ; while 
the large number of superior instruments sent out by our 
three most celebrated opticians, viz., Messrs. Powell and 
Lealand, Andrew Ross, and Smith and Beck, during the past 
year, testify to the fact that quality is in equal estimation 
with quantity. 
The three makers just named have su.pplied, during the 
past year, no less than 217 instruments of the higher class; 
whilst the last-mentioned firm has also sent out 175 educa- 
tional microscopes, of which 60 only were of their cheapest 
kind, making a total of no less than 392 instruments fitted 
for accurate scientific investigation. 
But even this number, large as it is, does not comprise the 
whole, or anything like the whole, of those that may fairly be 
classed under this category ; for there are now in London 
alone several makers who, though they may not as yet attain 
to the excellence of those already quoted, are treading so 
closely upon their heels, that the productions of those in the 
second rank closely approach those of our first makers as they 
were some few years ago. Consequently, to comprehend the 
entire quantity of real working microscopes put into circula- 
tion for the last twelve months, we should add those supplied 
by Mr. Salmon, Mr. Amadio, Mr. Ladd, M. Pillischer, and 
some others. The four makers quoted have collectively 
issued 115 of the large instruments, and 243 students^ and 
medical microscopes ; consequently this number, added to 
the 392 previously quoted, gives us a total (a mininum total) of 
750 brought into operation in one year ; for there are 
doubtless some not included in this list, — and be it understood 
that the whole of these were eflPective, working instruments. 
Surely this plentiful sowing ought to make us reap 
plenteously. 
With such exquisite microscopes as we have been for the 
last few years in the habit of using, anything like improve- 
ment might almost be regarded as ^' gilding refined gold 
yet progress has been made even here, and still the cry is 
" Excelsior.'' 
Messrs. Powell and Lealand have made an objective of 
very high quality, equivalent to -J^ inch of focal distance, of 
very large aperture (alleged to be of 175° — but of this here- 
after) — which for performance is deserving of the highest 
praise. 
Mr. Ross has constructed a |-inch object-glass of 140° 
angular aperture, having that great desideratum, a reasonable 
distance from the object under observation, and that possesses 
