720 KANSAS CITY REVIEW OF SCIENCE, 
The stations of observation are indicated in the cut by the small circles. 
Four of them have however been inadvertently omitted, viz: Carrollton, which 
lies on the 8° 30’ line; Glasgow, which is midway’ between the 8° and the 8° 30’ 
line; Columbia, which is just east of the 8° line, and Houston, which lies in the 
westward concavity of the 7° 30’ loop. 
Those wishing to secure a larger and more accurate map, with these lines of 
equal variation upon it, can obtain the fine township map of R. A. Campbell, of 
St. Louis. 
In conclusion it is perhaps proper to add that in the prosecution of this work 
we have received aid from many public spirited citizens of St. Louis and of the 
State. It having been found impossible to obtain from the Legislature the small 
appropriation necessary for finishing the survey, it is now at a stand. It is hardly 
reasonable to ask private citizens to carry on work which is clearly a matter for 
public enterprise. 
THE KANSAS CITY ELECTRIC TIME BALL. 
BY PROF. H. S. PRITCHETT, MORRISON OBSERVATORY. 
The first time ball established in the United Sates was dropped from the 
dome of the Naval Observatory at Washington in 1855. It is still dropped at 
Washington mean noon, and has for a long time furnished the standard time for 
the city and the Departments of the Government. The apparatus employed and 
the method of dropping the ball are extremely simple. At five minutes before 
noon the ball is raised to the top of the staff on the old dome of the Observatory. 
The signal which drops it is made by hand by an assistant stationed in front of 
the mean time clock in the Observatory below. The ball when released drops upon 
the dome and thence rolls to the roof beneath. 
The New York time ball, established in 1877, is dropped at New York noon by 
an electric signal, sent from the Naval Observatory at Washington. It was erected 
and is maintained by the Western Union Telegraph Company, and is dropped from 
their building on Broadway. At1zh. 55m. the ball it hoisted half-way up the staff 
on the tower of the building. At 11h. 58m. it is hoisted to its highest point, when 
it is about 250 feet above the street and can be well seen by the shipping at the 
New York and Brooklyn docks, and vessels in the bay and from suitable positions, 
is visible to a large part of the citizens of New York, Brooklyn, Hoboken and 
Jersey City. 
The ball is 3ft. 6in. in didmneter It is really not a sphere but consists of cir- 
cular pieces of metal joined together in such a way as to present the appearance 
of a solid ball when viewed from any direction. 
If on account of wind the ball fails to drop at 12h. om. os., it is held till 12h. 
5m. and then dropped. In such cases a small red flag is hoisted at 12h. 1m. and 
kept flying till 12h. 1om. This ball was for some time dropped by hand, but for 
