GENERAL MEETING. Tey 
Mr. T. Roprnson read a paper entitled— 
WAS THE EARTHQUAKE OF SEPTEMBER 19TH FELT IN THE 
DISTRICT OF COLUMBIA? 
[Abstract. ] 
At 3.20 p. m. of September 19 I noticed a peculiar vibration of 
the floor, table, and chair. I saw my ink shaking and heard the 
door of the room rattling. The table and chair rocked in a north 
and south direction. The sounds made by the door were at regular 
intervals of something less than a secondeach. My room is on the 
second floor of the Howard University building. 
Immediately after the occurrence I inquired if other persons had 
noticed anything unusual at that time. One had heard a rum- 
bling, another had felt the shock, and a third had both felt and 
heard it. The miners in the water-works’ tunnel also heard a rum- 
bling noise at about the same hour. 
From the motion of my table and chair and the continued thump- 
ings of the door I judge that the shock passed in the direction of 
the meridian, and continued from ten to fifteen seconds. 
There was no local cause for the phenomenon, and I concluded 
that it was in some way connected with the earthquake that oc- 
curred in the West at about the same time. 
Mr. Pav remarked that the direction of the motion communi- 
cated to buildings by a slight earthquake shock is not a reliable 
index of the direction of the earth tremor. The azimuth, ampli- 
tude, and period of vibration of the buildings are functions of their 
structure rather than of the azimuth, amplitude, and period of the 
earth vibration. 
Other remarks were made by Mr. H. A. Hazen and Mr. Evxiort. 
Mr. J. S. Bruiryes exhibited a collection of microscopes illus- 
trating-the evolution of the mechanical stage. The collection will 
be sent by the Army Medical Museum to the New Orleans Ex- 
hibition. 
Mr. Bruuines read a paper by Mr. WAsHiInGTON MATTHEWS on 
NATURAL NATURALISTS. 
[Abstract. ] 
It is easy to understand that a savage may be well versed in the 
knowledge of animals and plants which contribute to his wants, 
