IN RAIN AND SNOW IN THE UNITED STATES. XI 



Observations made undei' the direction of the U. S. Patent Office and the Smithso- 

 nian Institution, for the years 1854 to 1859 inclusive, Vol. I (Washington, 1861) ; 

 and the Annual Report on the Survey of the North and Northwest Lakes, for the 

 year ending June 30, 1867, by Bvt. Brig. General W. F. Eaynolds. Among manu- 

 scripts of large extent, those kindly furnished by Capt. (now Gren.) Gr. G. Meade 

 and Col. (late Lieut. Col.) J. D. Graham, Top. Eng. U. S. A., Superintendents of the 

 Lake Survey (1858-1863), and by Bvt. Major Gen. J. K. Barnes, Surgeon-General 

 U. S. A., for eight years (1860-1867), and subsequently for the years from 1868 to 

 1874 inclusive, were of great value, especially the latter, as comprising records at 

 the military stations situated west of the Mississippi, upon which stations our meteoro- 

 logical 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 manu- 

 script ; these, and the materials mentioned above, together with many series pub- 

 lished or communicated by public institutions or by private individuals, are incor- 

 porated in the following 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 the metric system, the latter has been changed 

 to the former for the sake of uniformity. 



DESCRIPTION OF EAIN-GAUGES AND DIRECTIONS FOR OBSERVING. 



Particulars respecting the kind of rain and snow gauge, the method of observ- 

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



Main-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 Register, 

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

 nished 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 instru- 

 ment 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 distance at least equal to its height, and still 

 further oflf 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 evapo- 

 ration. The measurement is made by putting down perpendicularly to the bottom of 

 the gauge the measuring stick and applying it from its j)oint to the water-mark on 

 the scale, which will express the quantity in inches or their decimals. The gradu- 



