METEOROLOGICAL OBSERVATIONS. 



601 



The barometric observations at Olympia are of a barometer noted by G. W. Stevens as con 

 taining air, in April, 1854. They have a large zero error, and the succession of readings is often 

 such as to prove that the errors of measurement are very large. The summaries would, there 

 fore, give no valuable data to judge of the mean position of the barometer then, or of the measures 

 of variation. 



The hygrometric observations are not embraced in the summary, as they can only be pre 

 sented accurately in deduction, or in detailed observations. The mean differences of the wet 

 and dry bulb are very small. In August, 1854, the mean difference at sunrise is but one and a 

 half degrees, at 2 p. m. 7.5 degrees, at 9 p. m. 3.2 degrees. In September, 1854, these differ 

 ences are, for the respective hours, 1.4, 4.3, and 1.5 degrees. These are the dryest months 

 except July. It will be seen that these results differ largely from the same measures east of the 

 Cascade range of mountains and at Fort Benton, and prove the coast atmosphere to contain a 

 large proportion of moisture at all seasons. In the rainy months, the differences between the 

 hygrometer arid the dry thermometer are very small. 



Summary of Meteorological Observations at Olympia, Washington Territory. 



* Observations to 17th only. 



T6/ 



