554 



REPORTS ON THE STATE OF SCIENCE. — lOlG. 



(4) Temperature of mercury barometer and ten readings taken. 



(5) Five readings of aneroid and its temperature recorded. 



(6) Observations (made by the ship's officer) of speed, course, depth, 

 Latitude and longitude. 



When the barometers pumped more than usual a larger number of 

 observations were recorded. 



In Talile I. are typical sets of readings. 



Taule I. 

 Typical Sets of Readixgs. 



Table II. gives the means of the land and harbour station observations 



which were used for the calibration of the aneroid. 



Table III. gives the observations made at sea. 



[These tables are not reproduced in full ; the original Eeport should 

 be consulted for details.] 



. 5. The Reduction of the Aneroid Readings. , 



The aneroid was not delivered to the experimenter until the eve of his 

 departure for Australia, when a test was out of the question. Fortunately 

 the instrument had passed through the hands of Mr. F. J. W. Whipple, 

 who had compared its reading with that of a standard barometer at the 

 Meteorological Office. Comparisons with the mercury barometer were 

 made at each port of call on the voyages, and subsequently in University 

 College, Reading, and at the Meteorological Office, London : Table 11. 

 The results show considerable changes in the value of the aneroid reading 

 corresponding to any particular pressure, the readings rising with time. 

 The problem has been to find the value in millibars of an aneroid reading 

 at any scage in the voyage. 



