of the observations, but tlie charts exhibit the various meteorological relations 

 and fluctuations in a much more striking manner. 



BAROMETRICAL OBSERVATIONS. 



The barometer in use is Fortin's model as made by Negretti and Zambra. 

 The internal diameter of the tube is approximately one quarter of an inch. Tt is 

 graduated in inches and read by vernier to thousandths. I find no record of any 



reliable comparison of it with a standard. As before stat< 1. if is mounted with 

 the level of the mercury in its cistern at a height of 84 feet above the sea level. 

 In the annexed tallies the readings are reduced to the fid zing point and to the 

 level of the sea. 



Table A gives the readings thus reduced for the entire year. The most 

 interesting results in connection with the barometrical fluctuations are to be 

 found in table B which is obtained by a reduction of the results in table A. In 

 this table will be found the means for each month of the records at 7 A3!. 2 P.M. 

 and 10 P.M. and also the annual mean of the same. A comparison of these means 

 points clearly to the existence of diurnal maxima and minima, the mean heights 

 for the year being respectively 29.977 inches at 7 A.M., 29.918 inches at -1 P.M., 

 and 29.962 inches at 10 P.M. It will also be observed that this same relation 

 exists in each set of monthly means, with two exceptions. It is hoped that a 

 series of frequent observations, to be undertaken in the future, will indicate 

 accurately the times of maxima and minima and determine the extent of the 

 diurnal oscillation. Table B also contains the general mean for each month and 

 for the year, as well as the maximum and minimum heights and the range for 

 each month. The greatest range during any month was in February, the amount 

 being 1.318 inches. The least fluctuation during any month was in Jul)", the 

 amount being .389 inches. The greatest barometrical height for the year was 

 30.515 inches which was recorded at 10 P. M. on April 21. The lowest point 

 reached was 29.087 inches at 7 A.M. Feb. 23., the range for the year being 

 1.426 inches. The fluctuations of the barometer during the entire year are 

 shown on the six pages of Chart No. 1. The first diagram of Chart No 2 shows 

 the fluctuations of the monthly barometric mean, and the second exhibits the 

 maximum, minimum, and range for each month of the year. On comparing these 

 barometric Charts with others which follow, representing various meteorological 

 phenomena, one is tempted to enter into various speculations which, however, it 

 is wisdom to defer until a series covering a more extended period than one year 

 can be obtained. 



