49 
Sept, i, 1885.] The Australasian Scientific Magazine. 
poles, a steel tube capable of holding the bar, and of equal length and 
weight, is treated in the same way, and the bar magnets, covered with 
insulating material, are inserted in the tube magnets, with the poles and cut 
surfaces reversed . Thus (^represents cut ends). 
These compound magnets are now mounted compass-fashion. They 
have no tendency as regards the poles of the earth, because that is 
balanced. But the tendency to move in sympathy is obviously doubled. 
Whatever the distance between them they tend to lie parallel. 
All that is necessary, then, to telegraph from the holder of one of a pair 
of magnets to the other, is a code of signals like that of the old needle 
telegraph. The sender moves his needle according to the code, and, its 
fellow moving in sympathy, the receiver reads off the message. Of course an 
exact duplicate as to form, hardness, and weight of either outer or inner 
magnet intervening, would cause a false motion or prevent communication, 
as induction does in a system of telephone wires. But such an accidental 
duplicate would obviously be more rare than an extra key to a Bramah 
lock, and this difficulty is practically never experienced by those clever 
natives of India, who use these and such means for retaining a supersti- 
tious influence over their more ignorant fellow-countrymen. 
In the south of Florida lies Lake Worth ; south of Jacksonville, by the 
waterways, 470 miles; and by schooner direct, 300 miles. It lies 
immediately along the Atlantic coast, in latitude 26° 40'. The lake itself 
is twenty-three miles long, and less than one mile wide, extending north 
and south parallel with the ocean shore, and separated from the ocean by a 
narrow strip of land generally less than half a mile wide. From the western 
shore of the lake, looking across the lake and strip of land, we can see the 
masts and riggings of ships sailing on the Atlantic southward, on the way 
from New York to New Orleans. Such vessels, going in that direction, 
keep between the Gulf Stream and the land. 
■ S 1 
■*N ) 
SEMI-TROPICAL FLORIDA. 
BY 
A SETTLER. 
