46 
ABBB. 
These afford a precious material for working out the relation 
between atmospheric movements on a large scale. The first 
steps in such generalizations were taken by Professor Gar- 
riott, to whom are due the conclusions given in “Weather 
Bureau Bulletin A, Summary of International Meteorological 
Observations.” 
Next we come to a series of charts published by Hilde- 
brandsson about 1895, showing the simultaneous departures 
in pressure at many stations over the whole globe. These 
tables and charts show that an excess or a defect of prassure 
may be observed simultaneously over a very large part of the 
globe, perhaps one-half or even three-quarters of its surface, 
while in other months the conditions will be nearly reversed. 
Inasmuch as he took monthly averages, he was not able to 
show the progressive movements of these areas of high and 
low pressure, if, indeed, they do move, as is fair to presume 
and as he would probably have discovered if he could have 
compiled daily or pentadic instead of monthly maps. 
But our observations have been largely confined to the 
earth’s surface and to stations near sea-level; we must go 
higher in the atmosphere. The importance of mountain 
stations and of balloon work was recognized a century ago, 
as shown by the establishment of several mountain observa- 
tories and by the early balloon voyages of Barral and Bixio 
and their successors. The numerous voyages by Glaisher 
added greatly to our knowledge, but the systematic work 
with both balloons and kites since 1893 has constituted a 
brilliant epoch in our study of the atmosphere. Although 
the kite had frequently been used by Franklin and other 
electricians during the previous forty years, yet its use to 
carry thermometers to great heights dates only from Alex- 
ander Wilson, of Glasgow, 1780. A century later it was em- 
ployed in England to study the upper winds by E. D. Archi- 
bald. The invention of the Hargrave or box kite and 
the improvements introduced in every detail by Pro- 
fessor Marvin, and to a less extent by others, have 
converted the kite into a most important meteorologi- 
cal apparatus. Meanwhile the use of a small balloon 
