REVIEWS. 423 
above named, but first in time, is noticed here merely to illustrate some 
statements ionge en as though there had been no contra- 
diction of t Ther no other course left for those who know 
him to be wrélig or na asia ed by his statements, than to examine 
his qualifications for pronouncing judgment, and to show wherein he is 
mistaken 
P ign n being a man of acknowledged scientifle acquirements, and 
holding a reputable position at Cambridge, his opinions, given on a 
lished in a journal of high repute in Europe, will command attention inh 
respect there, among those who have no opportunity to see and judge for 
left to itself to refute his “ opini " No one can object to any compar- 
son of American instruments with others; it is only asked that the com- 
parison shall be made fairly, and by a competent expert. e iter 
proposes to show that Dr. Hagen's investigation has been superficial and 
inadequate to the task he undertook; and that he has mistaken facts and 
repeated assertions after he had been informed that they were erroneous. 
- Hagen opens his first communication to the Boston Society of Nat- 
perfecting of the instrument —I was anxious to examine the power [? ] 
of American microscopes." This passage sets forth his claim to be a 
Voy hing cr um ic. 
* During the past ten years there has been great competition among 
opticians, dn in every case wn progress has been arrested by one in- 
surmo emi obstacle." [What one?] ‘Since the recent improvement 
in c ing objectives for ie thickness of covering glasses, compara- 
iei ica has been done.” Why he should have restricted the “ great 
competition " to the last ten years, and called the improvements in objec- 
tives 
years ago, can only be explained by supposing what has been generally 
believed to be the fact, that the “improvement” and the competion had 
that the London retta Society, which procured gagne of the 
"three" leading London a s in about the year 1845, in 1867- 
doned the whole of them as ioa the times, and obtained new ones of 
the same makers. 
