VARIOUS APPLICATIONS OP TELEGRAPHY. 2% 
of M. Leverrier, the Observatory of Paris has supplied fore¬ 
casts which are published periodically. M. St.-Claire Devi lie, 
believing that Algiers is the centre from which emerge all the 
storms that pass over the Mediterranean, has made great 
efforts to establish posts of observation in that colony, which 
are regularly at work and are of great utility. 
To Admiral Fitzroy is due the idea of forecasting the 
weather, and announcing coming storms and tempests some 
time in advance. He proposed to the English government 
the establishment of twenty meteorological stations on the 
coasts of the United Kingdom, which were to furnish the 
data for his forecasts. 
It was a difficult matter to overcome the incredulity with 
which this project was at first received ; but his first predic¬ 
tions were so exactly verified, that by aid of the maritime 
insurance companies, all the English ports were soon provided 
with a meteorological station. 
Admiral Fitzroy’s forecasts were based on an exact scientific 
system, and it would be unjust to confound them with those 
of the modern prophets whose predictions appear monthly in 
certain minor French periodicals. Admiral Fitzroy explains 
his theory in a paper he has laid before the learned societies. 
He says that, as ordinary meteorological instruments com¬ 
monly indicate important changes several days in advance, we 
may foretell the weather and the direction of the wind we 
expect the next day at a given place, from the morning 
observations, compared with those of the preceding days. We 
take the mean of these local indications to form that of the 
districts, and we then calculate what the result should be. On 
a map we place moveable arrows to show the direction of the 
winds, and the possibility of cyclones, and we observe their 
course and the movement of the wind about their centres, 
according as they meet, combine, or recede. 
WTien the condition of the weather has been decided for all 
parts of England, notice of expected gales is sent to the 
threatened ports, at which alarm signals are immediately 
hoisted up, indicating the direction an I force of the gale 
expected. 
The French Meteorological Department also gives warning 
