4 SCIENCE PROGRESS. 



of the Palatinate in the pubHcation of the Mannheim 

 Ephemerides, In 1801 appeared Colonel Capper's work 

 (4) upon the results of his observations upon the coast of 

 Coromandel, in which he lays down the circular character 

 of the motion of the winds. 



In 1820 Professor H. W. Brandes of Breslau pub- 

 lished an important work {5) in which he discussed, with 

 great labour and skill, daily records for the year 1783 from 

 thirty stations, twenty-eight in Europe and two in America. 

 It is curious to notice how closely he approached modern 

 methods ; for instance, a storm and barometric depression 

 passed from the British Isles to Berlin from about the 6th 

 to the 9th of February, and although in his book he does 

 not give a chart, it is almost certain that he must have 

 drawn one, with something identical in appearance with our 

 modern isobars. The modern practice of reducing baro- 

 meter readings to their equivalent sea level pressures had 

 not been thought of, but instead. Professor Brandes adopted 

 the plan (much later employed by Buijs Ballot) of express- 

 ing the readings as departures from the average. To show 

 how thorou8;hlv he had seized the idea of isobars a few 

 words must be quoted : — 



"Am tiefsten, namlich 14 Linien unter der Mittelhohe 

 stand das Barometer in Lyndon in Rutlandshire. Die 

 gegend, wo es 13^ Linien unter der Mittelhohe stand, 

 lasst sich durch eine Linie bezeichnen, die etwas westlich 

 von Franeker, genau liber Amsterdam und dann ver- 

 muthlich das siidliche England geht. Die Linie wo es 13 

 Linien zu tief stand, geht noch oberhalb Mittelburg, iiber 

 den Canal, nach dem franzosischen Hafen St. Malo." 



Professor Brandes similarly traces the lines joining the 

 gradually less and less depressions until he reaches a de- 

 pression of only three lines at Bologna and Rome. In 

 another place he regrets that he had not sufficient informa- 

 tion similarly to study the direction and strength of the 

 wind, he says that where the barometer was lowest the 

 wind was strongest, that the depression occurred earlier 

 on the Atlantic coast than in the East, and he anticipated 

 the modern idea of barometric gradient by comparing the 

 depression at different places and dividing it by their dis- 



