Grass Valley could be used to hold, as a reservoir, the surplus water from the Grass Valley Mountains in the spring, a large quantity of which now runs down the Santa Clara River, and no use whatever is made of it.

It is estimated that enough water could be stored to irrigate 2,000 acres at a cost of $10,000 by making a dam across Grass Valley.

There are good places at the mouth of Pinto Cañon for a reservoir to hold the surplus water from Pinto Mountains, and plenty of good land close by on which to use it.

Little Pine Valley, near Hebron, is also another good place for a reservoir, large quantities of surplus water running to waste in the spring from that section of conntry.

Dameron Valley, 12 miles north of St. George, could be used to store the surplus water of the Pine Valley branch of the Santa Clara River; this water would be very valuable to the city of St. George, which has the least amount of water for the num ber of inhabitants of any city or town in Utah.

Clay and sandy soil require about the same amount of water. Sandy land requires more at each watering but does not need water as often as the clay land.

Crops need water in the lower part of our county every seven days, aud the water should run for at least three hours; in the upper lands of the county once every fourteen days is sufficient.

The Rio Virgin is the most important river passing through our county. At the present time there is not more than 4,000 inches running below Price Canal. It is now our low-water season which usually lasts from the 15th of June until the 1st of September. Some portions of the year large bodies of water flow down caused through the melting of the snows and summer storms. The water of the Santa Clara at this time of year is all used by the Santa Clara Irrigating Company.

You will perceive that our seasons are very long in this section of the country, and in consequence where water is plentiful and land good we raise very heavy crops. We can cut four to five crops of lucern.hay per year. Wheat and barley are harvested early in June, and a crop of corn raised on same land, thus you see we can raise two crops on same land per year where water is plentiful. Grapes, peaches, almonds, and such crops grow almost to perfection. All we want is water to put on the land, an abundance of which passes out of our country each spring unused.

Santa Clara irrigating district and St. George City lose at least on an average onethird of their crops each year for want of water; this loss could be saved if water was stored in Grass Valley, Little Cone Valley, and Dameron Valley as described. NOTE. The water measurement in this country is made on the "Weir Dam" system with 4-inch head.

On behalf of the county court, Washington County.

THOMAS JUDd,

MARTIN SLACK, Special Commissioners.

After receipt and filing of these reports, the committee adjourned.

Washington County canals-Acres irrigated and cultivated, etc.

THE RAIN-FALL AND CHANGES IN GREAT SALT LAKE. 125

EXPLANATION OF PROFESSOR MARCUS E. JONES, DESERT UNIVERSITY.*

In the diagrams of the rain-fall of Salt Lake City, and of the oscillations of Great Salt Lake, already presented, the curves are made by letting a square (composed of four squares of the profile paper) represent a year between its vertical sides, and between its horizontal sides representing an inch of rain-fall and a foot of oscillation in the lake. The fine lines represent tenths of an inch of rain-fall and tenths of a foot of lake oscillation, respectively. The rain-fall of each year is drawn to the right side of the square representing that year. The unbroken lines represent known curves, while the dotted lines are hypothetical. The dotted rain-fall lines are merely tentative and may need revision, but there is not sufficient time for me to do this now. It issufficient to say that they are more liable to be too high than too low. As my object is to arrive at the normal rain-fall of Salt Lake City, and so of the whole arid region (for the relation of our rain-fall to the rest of the arid region is pretty well known), the conclusions drawn from these diagrams are sure not to be too low, and therefore the irrigable land in the arid regions that can be supplied with water by our normal rain-fall is equally sure not to be underestimated and is doubtless somewhat less than I have given it below.

The lines thus drawn from one square to another gives a graphic curve which shows to the eye irregularities that would not easily be perceived otherwise.

A comparison of the rain fall curve of Salt Lake City with that of the whole country will show a general conformity, but with local minor variations. The most noticeable feature is that our wet and dry seasons come on the next year after they occur on the Atlantic coast. From the fact that climatic changes are continental it is possible to determine from the rain-fall curve of the whole country what the rainfall of Salt Lake City has averaged as far back as 1800, by finding the relation of our rain-fall curve with that of the whole country from 1855 to the present.

The diagram of the Salt Lake City rain-fall is based on the records of the Signal Service since 1875, and on those of the post surgeon at Fort Douglas (3 miles east of this city) for the five preceding years, and on the records kept by W. W. and H. E. Phelps from 1855 to 1869. The Phelps records were carefully kept, but there appear many clerical errors in them, as published by the Smithsonian Institute and the Signal Service. Whether these errors were made by the observers in copying them, I do not know. I have therefore discarded the Smithsonian records and taken them as they were made out here, with here and there the correction of typographical errors. These records are uniformly too low by an inch, as shown by the oscillations of the lake, but this is chargeable to the poor quality of the instruments used in those early years. The rain-fall of Fort Douglas since 1877 (kept very carefully) is nearly 2 inches above that of Salt Lake City per annum, but previous to that time they were not carefully kept, and so to avoid understating our rain-fall, I have put the Fort Douglas records into the diagram at their full value.

In getting at our average rain-fall since 1800, we find that the average height of Great Salt Lake since 1884 has been about 7 feet above the Garfield zero. The annual rainfall since that time that has had to do with the oscillation of the laket has been about 15.4 inches, but the average height of the lake since 1840 has been over 1 foot below that of 1884 to the present, therefore the average rainfall of this place since 1840 is not above 14.5 inches. By referring to the diagram of the rain-fall of this country, prepared by Charles Schott of the Smithsonian Institute (a copy of which is presented) it will be seen that the normal rain-fall of Salt Lake City for the last fifty years has been in excess of the normal for the century by an inch or more, since the rain-fall for the whole country for the last fifty years has exceeded considerably the average for the century, therefore it is quite probable that the average rain-fall of Salt Lake City since 1800 has been but little above (if not below) 13 inches per annum. On this basis there are but 300,000 acres that can be cultivated in Utah to-day without additional reservoirs, estimating the duty of water at 1 cubic foot for 80 acres, and if the whole water supply that falls in the winter were saved we could cultivate 600,000 acres, but it will be impossible to save more than one-half of our winter rainfall. Utah has a greater water supply, and, therefore, irrigable area than either Idaho, Nevada, Arizona, or most of New Mexico. With an annual rain-fall of 17 inches in the last ten years Utah has only 500,000 acres under cultivation, and this, too, with all of the unreservoired water supply fully used, with the exception of the waters of the Grand and Green Rivers, which can not at present be utilized from lack of capital.

"Referred to in Prof. Jones's testimony (pages 172-175) and since forwarded to the committee by him.

The very abnormal rain-fall of November and December, 1869, will be felt in 1890 and so does not belong in 1889.

Added to his diagram (which stops at 1800) the rain-fall of Philadelphia up to 1887 and that of Salt Lake City up to 1890, to make it complete.

Salt Lake City has over twice the rain-fall of the valleys of Utah, Idaho, Nevada, Arizona, and New Mexico west of the Sandia Mountains, and the western half of Wyoming and Colorado. There are but three mountain ranges in this whole region whose snow-fall even slightly exceeds 40 inches of water in fall and winter, and the majority of the ranges have not over half of this snow-fall. On the loftiest of these ranges the snow belt never exceeds 20 miles wide, while in most of them it is very narrow. Viewed from the stand-point of the actual rain-fall of the arid regions, it becomes evident at once that it is impossible to irrigate even 10 per cent. of the 1,000,000 square miles that it is said may be reclaimed by irrigation. It is not probable that more than 10,000,000 acres can be reclaimed by any of the present methods of irrigation that are practicable on a large scale (subsoil irrigation, as at present conducted, is not practicable for general farming because of its great cost) in the arid regions, while the Salt Lake City rain-fall averages 17 inches per annum; while the sub-arid regions, embracing eastern Wyoming, Dakota, western Nebraska, eastern Colorado, western Kansas, eastern New Mexico, northwestern Texas, and parts of California will not bring the whole area up to 64,000,000 acres, i. e., 10 per cent. of 1,000,000 square miles. But the fact that our irrigable area is so small makes it all the more imperative that the people of these regious should receive the aid they so greatly need.

To look at the irrigation question from the stand-point of the actual rain-fall is, in my judgment, the proper way, and this will at once show up the chimerical schemes of people who assume, without reason, that all they need is irrigation ditches, costly reservoirs, and tunnels run far into the mountains, and at once the fountains of waters will be opened and fill them. We can not get more water out of the mountains than falls upon them, nor can we save much more than half of what falls upon them.

The greatest needs of the arid regions to-day are elaborate experiments on the best methods of economy in the use of water (this in my judgment far overtops all others); erection of dams to utilize the larger rivers (like the Snake, Green, Grand, Rio Grande, Colorado, etc.), the building of reservoirs, uniform laws on water rights, uniformity in the methods of measuring water and in gauging streams, and the establishment of many signal stations in the valleys, and many places also in the mountains for the measurement of snow in winter.

As to the future of the arid regions, an inspection of the diagrams will give some valuable suggestions. From these it is evident that there have been two periods since 1800, one of twenty-four years of deficiency, and one of thirty-seven years of We are now fourteen years along in a period of deficiency, and it is quite probable that we may have a decade more of deficiency before we have a long-continued excess.

excess.

It also appears that from the crest of the greatest waves of climatic change to the bottom (1808 to 1825, 1835 to 1862, 1862 to 1881, and 1881 to -") there are usually three smaller crests between; there is an abnormality in 1830, and an apparent, but not real one, in 1867. The diagram of Great Salt Lake shows that within these second minor crests there is a third series of three years each of comparatively uniform movement either toward excess or deficiency; sometimes there are two sets of deficient or excessive years in a downward or an upward movement, with a break between, bat generally a series of three deficient years is followed by a series of three years of

excess.

From these facts it is perfectly evident that there are oscillations in our climate. It is also evident that they are not uniform like the movements of a pendulum, and these changes are due to causes which it is out of place to discuss here.

Looking at the future with the evidence of the past, it is probable that we have not yet reached the end of the period of deficiency. Great Salt Lake is still 3 feet above its old level, and it is more probable that it will return to it before beginning its next grand upward movement. Be this as it may, it is reasonable to suppose that within the next fifteen years we shall enter upon a long period of general excess in our water supply over the normal for the last one hundred years, but not an excess over that from 1850 to 1875.

From these diagrams it is equally evident that from 1839 to 1860, when the prairies of the great West were still unturned by the farmer's plow (or but slightly on the eastern side), the rain-fall of the whole country increased, while from 1860 to 1881, the period when the great prairies of Iowa, Missouri, Minnesota, Dakota, Nebraska, Kansas, Arkansas, Texas, etc., were transformed into fields of waving grain, the rain-fall rapidly decreased, and even to the present has been below the normal.

The deserted ranches of the plains to-day also tell a sad story of the weakness of man's power to produce climatic changes, and it is hardly worth our while to plant ourselves in the desert, turn over the sod (if there is any), and expect the heavens to be opened in rain for our benefit and as a reward for tilling the soil.

*Period of oscillation yet incomplete.