i 
Miscellaneous Intelligence, 285 
tor, because in the object glass of the latter, there are four surfaces lia- 
ble to the defects already alluded to, while in the reflector of the for- 
mer there is but one surface. ‘These facts and opinions I give with 
Course among the intelligent of the nation this belief has passed away. 
1847, 
4. Meteorite of July 14, 1847.—A meteorite exploded on the 14th 
Jaly, 1847, and threw down two or more fragments at Braunau in Bo- 
hemia. One fragment weighed forty-two pounds and a half; the other 
which weighed thirty pounds penetrated the roof of the house of a 
laborer, but did no harm to the inmates. 
V. MiscELLANEOUS INTELLIGENCE. 
1. Association of Geologists and Naturalists —We continue in this 
number the publication of abstracts of articles read at the last meeting 
at Boston, so far as they have been sent to us by their authors. Of a 
large number of memoirs, we have yet no notice for our pages. We 
should state that the closing paragraph of the Proceedings in our last 
Humber, page 116, was editorial. ‘The Proceedings will be continued 
Ina following n i are favored with other abstracts. 
—I am so much pleased with the excellence of an objective recently 
made for my microscope by an American artist, Mr. Spencer of Can- 
astota, N. Y., that I wish, if it is not too late, to append a few remarks 
to those which I made concerning the qualities of the microscope made 
by the same gentleman for Dr. Gilman.* The object which | have used 
in testing the powers of quite a number of the best microscopes In the 
Country, is the Navicula hippocampus, for English specimens of which 
Tam indebted to Wm. C. Williamson, Esq., of Manchester, England, 
4N accurate microscopic observer, who sent it to me as . the test object 
par excellence.” ‘hat it is so considered by the English observers, 
how by the testimony of several members of the London wrk 
Society, and indeed it is alluded to in a late address by the President ce) 
that Society as one of the most difficult test objects. This object one 
delicate longitudinal and transverse lines, the former of which are easily 
resolved by microscopes of ordinary quality, but the latter require 
defining power to show them at all. 1 have employed these lines upon 
the same individual shell, in examining several imported microscopes 
made by Chevalier, Oberhauser, Plaessels, Ross and Powell, and | have 
No hesitation in saying that the lenses made for me by Mr. Spencer are 
Superior to any which [I have yet seen, made by the three first eva 
Opticians ; the superiority consisting in much better defining power, anc 
na larger angle of aperture. With my own Chevalier microscope, it 
* See this Number page 238. The above letter came to hand after Dr. Gil- 
man’s article was in type.—Eps. 
