IN RAIN AND SNOW, IN THE UNITED STATES. 5 



by Capt. (now Gen.) G. G. Meade and Col. (late Lieut.-Col.) J. U. Graham, Top. 

 Eng. U. S. A., Superintendents of the Lake Survey (1858-1863), and by Bvt. Maj.- 

 Gen. J. K. Barnes, Surgeon-General U. S. A., for eight years (1860-1867), were of 

 great value, especially the latter, as comprising records at the military stations situ- 

 ated west of the Mississippi, upon which stations our meteorological information for 

 the western part of the United States almost wholly depends. The records of the 

 Smithsonian observers from 1860 to 1868 were available in manuscript; these, and 

 the materials mentioned above, together with many series published or communi- 

 cated by public institutions or by private individuals, are incorporated in the fol- 

 lowing tables and reductions. 



The unit of measure of rain-fall is the English inch ; in the few exceptional 

 cases in which the record is given in units of {he metric system, the latter has been 

 changed to the former for the sake of uniformity. 



DESCRIPTION OF RAIN-GAUGES AND DIRECTIONS FOR OBSERVING. 



Particulars respecting the kind of rain and snow gauge, the method of observing, 

 and other remarks and directions, will be found in the following extracts. 



Rain-gauges at the Military Posts of the United States, and Regulations for their 

 Use. — The following extract is from the preface of the Army Meteorological 

 Eegister, from 1831 to 1842 inclusive (Washington, 1851): "In 1836 rain- 

 gauges were furnished to many of the posts, by which the daily falls of rain and 

 snow would be measured, and entered upon the tables in inches and fractions of 

 an inch. The instrument employed is the conical rain-gauge of De Witt ; and 

 observations are ordered to be made immediately after every shower or fall of rain 

 or snow. The following are the instructions issued by the Department for its 

 observers : The instrument used to measure the quantity of rain which falls is the 

 conical rain-gauge. It is to be kept remote from all elevated structures, at a dis- 

 tance at least equal to its height, and still further off where it can be conveniently 

 done. It is to be suspended in a circular opening, made in a board, which is to 

 be fixed to a post, eight feet from the ground ; the opening to be five inches in 

 diameter, and bevelled, so as to fit the cone of the gauge, into which the conical 

 cap is to be placed, base downwards, to prevent evaporation. The measurement 

 is made by putting down perpendicularly to the bottom of the gauge the measuring 

 stick and applying it from its point to the water-mark on the scale, which will 

 express the quantity in inches or their decimals. The graduation of the scale is 

 by hundredths of an inch for the first three-tenths of an inch, and above that by 

 tenths and half-tenths. Parts of degrees will be measured by the eye, and set 

 down in decimals. If a rain continue for any length of time, the quantity in the 

 gauge will be measured at suitable intervals, before the water rises high in it, and 

 the measurements summed up at the close. 



"In freezing weather, when the rain-gauge cannot be used out of doors, it must 

 be taken into the room, and a tin vessel will be substituted for receiving the snow, 

 rain, or sleet that may then fall. This vessel must have its opening exactly equal 

 to that of the rain-gauge, and widen downwards to a sufficient depth, with a con- 



