WCP1638

Columbia July 18th. 1853

Dear Alfred,

The multiplicity om [of] professional duties¹ must be my excuse for not writing before. I received you[r] letters, one dated March 24th., and the other April 28th., containing the valuable imformation [sic] concerning the flume, etc. which is exacly what I wanted, my main object being to get the method of calculating the amount water discharged throug[h] a given channel at a given grade. I could get at the velocity of the water at the suface, but that would not g [sic] give the mean velocity which was required to calculate the discharge. I had also observed that theory could not be relied entirely, or that flumes of proportional sizes and grades would not discharge the same proportion of water. Thus the upper flume on our work, which was completed about this time last year, has three times the amoun[t] of fall that the lower one has. It was consequently predicted that it w [sic] would carry three times the amount of water, and many thought it would considerably exceed that proportion. I, however was not of that opinion, and although I had no way of calculating and could not even explain my mode of reasoning, I maintained and expressed the opinion that it would not carry three times the amount of water, but that I thought it would be rather more than double, and I expect you are right while your calculation shows that it would be less than double, and I expect you are right. The water in the flume does not keep the same height and velocity in every part, from the fact that although it was orrigially placed on a regular grade, the numerous settlements in the banks etc., have considerably altered the relative slopes of different parts, and although the sides of the flume are 22 inches deep, we cannot carry more than an average of 18 or 19 inches of water in some places it will be quite full, while at others it will not be more than 10 or 12 inches deep: with of course, a greater velocity. There is no difficulty in filling the flume at the head, as owing to the slope we have there the water does not run more than 5 or 6 inches deep, and yet fills the flume a little farther on, our only difficulty from leakage is the softening of the banks causing the flume to settle when, if it is not immediately attended to, the water gullies out a hole, the flume sinks down, and the whole rush of water is precipitated down a steep bank, carrying ea [sic] [2] earth, stones, trees and everything before it, leaving a yawning chasm of bare rocks to ge [be] bridged over before any more water can be carried on. The evaporation is considerable, but cannot be avoided, and it onle [sic] affects us when the water is very low in the river, and we have not enough to fill the flume which is the case for about two m [sic] months during the year. You seem to think we have fall enough to carry any amount of water, but we could easily dispose of twice or three times the amount if we could only obtain it. In my quarterly report, read at the meeting in June, I stated the amount of water delivered to be 10 million gallons every 24 hours, by the calculations you send I see it would make it about 11½ millions. Now, considering that I had no accurate mode of calculation, and scarcely any data to go upon, I may congratulate myself upon my being so near the truth, and consider myself considerable of a Yankee at guessing.

You seem to have a wrong idea with respect to our reservoirs; al[l] the reservoirs we have are used for holding the waters that runs through the main flume during the night, and on Sundays, so that we distribute the whole of the water that runs in 24 hours². During the day time the water is of coursed drawn off from the bottom of the reservoir by means of a gate, and a long wooden spout laid through the bottom of the dam, so that you see there is no difficulty in getting the water out of the dam, especially when we have the pressure of abut 20 feet head of water. Your calculations are of course only applicablet to water flowing in a flume, as I find that a ditch or Canal of the same slope requires nearly double the capacity of the flume to carry the same amount of water. We have been very unfortunate in our opperations lately,[.] About 6 weeks ago one of our largest reservoirs, situated about ½ mile from the town suddenly burst just before day light in the morning, and the whole rush of water mixed with mud, stones, logs, trees etc., came crashing through the center of the town, filling several houses, and causing many serious and some ludicrous scares, damaging stores and provisions, wearing apparel, and sundries, filling up miners holes, and carrying off their tools, etc. A committee of our company was immediately formed to estimate the amount of damage sustained by each individual, and to make compensation[.] to The whole amount of damages which we have paid for is about eight thousand dollars, and ther[e] are a few small accounts yet unsettled. I had to set to work and construct a new dam, which I got completed in 3 weeks, at a cost of a little [3] less than 4 thousand dollars. This reservoir will hold about 8 million gallons of water. Since then we have had several breaks in the flume, owing to leakage, so that I have been very busy, and have had scarcely an hour to myself self [sic] for the last two months. or I should have answered yo [sic] your two letters sooner. Your previous letter was received with my mother[']s³ account to the little female dog which was so mysteriously found and lost, which was was [sic] particularly interesting!

I was much pleased with Mr. Wilson's⁴ letter in the "The Times"⁵. It is bold and well written, and I hope may bring him into more notice. The latter part is particularly rich. "The poor broken screw bossed feathered and tortured" etc. is first rate. I think, however there is something wrong in his statement th[a]t water increases in force in an equal ratio with then square of the depth " or else I do not understand his meaning as well as the example by which he illustrates it. You have not explained to me either, the principle of his wing proller propeller⁶. or whether ther[e] is anything particularly new except the diagonal position of the propeller. The lifting the ship is all very well, if you can only do it so as to make any difference in the water line of the vessel, but I do not see how your example of the paddle wheel can act that way, as for every paddle passing on the water tending to lift the vessel up there is a corresponding one rising out of the water, tending to draw the ship down, so that I should think one would balance the other. Your idea of a square bow etc. is nearly carried out int[o] the large American River steamers, which only draw from a foot to eighteen inches of water.

I shall be pleased to receive a copy of your work when published⁷. The American people have an eye towards the valley of the Amazon, and a surveyingng [sic] expedition has lately returned from ther[e] and I belive there is a pamphlet pub*lished [sic] on the subject, by, I think, Lieut[enant]. Murry⁸, but I am not sure that is the name. Your request for a daguerreotype before I commenced shaving came too late, as I commenced a week or two previous, but I have had one taken as I now am, not in miner[']s costume, as I am not now a miner, but in a surveyors dress as I usually wear. You will no doubt pronounce the picture vilely done, and it is certainly not very good, but it is about the average quality they do here[.] I should like to have one in Thomas'⁹ best style as a specimen of English art. I will send mine by the same [4] mail as this, directed to my mother, so that if it does not arrive, enquires may be made for it.

By th your next letter I should like to have some statistical imformation [sic] respecting the London Water Companies such as the amount of water they each deliver in 24 hours, with the expense of construction, etc. And if you could ob [sic] obtain it I wouldd like to know the amount delivered by the Croton Water Works¹⁰ in New York, as well as the amount used in other American cities, such as Boston, Philadelphia, New Orleans etc., but I expect it will be very difficult to obtain such imformation [sic] in England.

I have a few beetles, collected, but am at a loss how to send them. I will however dispatch them in the course of a week or two, somehow or other.

Do you know, hear, or see anything about the Spirit Manifestations¹¹ in England. It is all the rage here just now, and numerous and wonderful are the revelations that they make. I have not yet had any opportunity of testing or examining the subject, but from what I can hear it appears to be a kind of Mesmerism¹² acting on inanimate object or a curious instance of mind acting on matter.

I h[a]ve nothing more if interest, to communicate at present, so hoping you will write often and long, I remain

Your affectio[n]ate brother | John Wallace

P. S. I enclose in the Daguerreotype case a beetle with very long antennee [sic], the body 7/8 of an inch. I am afraid he may be injured by the pressure, but I thought it would be the safest way to send it.