614 RISE AND FALL OF THE COLUMBIA RIVER. 
RISE AND FALL OF THE COLUMBIA RIVER AT FORT VANCOUVER. 
Wasuineton, D. C., November 7, 1854. 
Sir: I enclose herewith a letter from Mr. John D. Biles to Mr. Gibbs, explanatory of an ac- 
companying table of the rise and fall of the Columbia river at Fort Vancouver during the “ spring 
rise.” Mr. Biles was of my party in that country last year, and I know that perfect reliance 
may be placed upon his results. 
As the information is of value in more than one regard, I would request that it may, if possi- 
ble, accompany my reports. 
I am, sir, very respectfully, your obedient servant, 
GEO. B. McCLELLAN, 
Lieutenant Engincers and Brevet Captain. 
Capt. A. A. Humpureys, 
In Charge of Pacific Railway Office. 
Coast Survey STaTIoN, NEAR CamMpEN, MatIne, 
; November 1, 1854. 
Dear Sr: Ina letter from George Gibbs, Esq., dated at Steilacoom, he sends observations 
on the freshets observed at Fort Vancouver by Mr. John D. Biles, and intimates that they may 
be useful to you. I send, therefore, a copy of the tables, and of Mr. Biles’s letter. 
Yours, respectfully, 
A. D. BACHE. 
Capt. McCLeixan, 
Corps of Engineers. 
Wasuineton Territory, Cotumpia Crry, 
August 20, 1854. 
Dear Sir: Enclosed I send you the observations of the Columbia river during the freshet 
commencing May 8, 1854, and ending July 20. I also observed the temperature of the air and 
water at the same time. The observations of the river were measured by a common two-foot 
rule. I presume you will easily understand the register. The figures in the column headed 
“rise,” show the amount of water each twenty-four hours; that is to say, May Sth the river rose 
two inches, May 9th two and a half inches more, and so on, as registered. The figures under 
the column headed “ fall,” the same way. 
You will also observe, by the register, that on the 7th day of June the river commenced to fall, 
continued till June 16, and during that time fell three feet one and five-eighths inches. The 
water was not so high this year, by four feet, as last year, and the year before. The convexity 
of the river, at its highest, was, as near as I could judge, ten inches, and during its fall, about eight 
inches. The velocity in the channel at low water is one hundred yards in two minutes and 
twenty-two seconds; at high water, one hundred yards in one minute and thirty-eight seconds. 
It was impossible to measure the deposit, as it was such a small quantity, in four gallons of 
water. I have preserved every particle, and enclose each observation in a separate paper. The 
one marked May 31, was taken when the river was rising; the paper marked June 30, when the 
water was at its highest; and the one marked July 20, in its general stage. I also take one 
to-day, August 20. I could not procure scales accurate enough to weigh them, thinking you 
could weigh them after you receive them. Each package contains the amount of deposit of four 
gallons of water. If there is any part of the observations you cannot make out clearly, inform 
me, and I will give you all the information I possibly can, with pleasure. I shall comply with your 
