come one can readily see, and to those who find it difficult to keep up with their present correspondence these will stand out prominently. Nevertheless, it would seem as though it would be worth while trying. If instructors and students do not take to it, then it should go the way all things go for which there is no demand or for which no demand can be created.

(6 and 7). Collection and exchange of museum and other illustrative materials. We have finally arrived at the topic which no doubt was chiefly in mind last year when the motion was made for the appointment of the committee-the exchange of illustrative materials. The oretically it seems a nice scheme. It seems as if instructors in the earth sciences, widely scattered, could arrange a scheme of coöperation in the exchange of rocks, minerals, soils, and of museum materials of various kinds arranged in series showing the stages from the original raw material to the manufactured product. It would seem that grains, such as rice, corn, wheat, oats; fibers, such as cotton, wool, flax, hemp; minerals, such as iron, copper, nickel, lead, graphite, and other material, such as rubber, paper, sugar, naval stores, and many other things might be gathered in this way and exchanged. With these should go photographs showing the various stages in the progress of the raw materials to the finished products. Many of the things mentioned are heavy, and a systematic exchange of such materials would necesitate establishing a convenient center to which the materials could be shipped and made up into the proper form. When a sufficient collection had been gathered together different sets could be shipped to each individual coöperating. It would seem as if the entire time of one man might be taken up with gathering, arranging and shipping such materials.

It would seem that those who have constructed models could easily make copies from the moulds and that they might be exchanged direct. Your committee hoped to receive replies from several who we know have made models. We thought that they would be willing to make copies for exchange but we have been disappointed. No doubt, however, with the movement once started, there would be greater freedom in offering, and probably more models would be made were it known that they could be exchanged for others. The present high price of models is a good reason for such a coöperative scheme of exchange.

Almost everybody, whether working in geography or not, has a camera. With the thousands of cameras working in various parts of the world, it would be surprising if exchange of pictures could not supply to all of us those which we need. It ought to be possible to satisfy specific wants through correspondence with individuals, or perhaps better still through communication with some central body in touch with all. Your committee has endeavored through correspondence and through conversation to learn what are the unsatisfied demands of the teachers of the earth sciences and what each one can contribute toward a common or individual need. The returns are enough to convince us that there will be no spontaneous and immediate general participation in a movement to supply materials. If this is to be successful there must be selected out ten or a dozen or fifty people to do

the work in each country. It is plain that where people are as busy as we are, anything which lies outside of our immediate duties as teachers is likely to be neglected. This gathering of material does lie outside of these duties. The gathering of information lies right alongside of our immediate duties. The study of the interests and needs of the student is an immediate duty.

II. Legislation. In these days of agitation for railroad rate legislation it may not be shocking to propose rate legislation which shall favor the field excursion for educational purposes. It may be hoping for the impossible, but is it not true that transportation for educational purposes should be put on a different basis from transportation for business purposes, and is it not possible that concessions may be wrung by legislation from the railroad officials who resist like adamant the appeals from educators for rates as low as those granted to theatrical troupes?

III. Coöperation as to positions. It is looking far into the future, perhaps, and is but putting a dream into words to speak of a system of international migration of instructors in geography, so arranged that in the course of ten years or so one could have resided in several different countries and climates and arrive at the original starting point with a rich store of knowledge and the power of arousing enthusiasm in the student of geography such as can be aroused by one who has had adventures in strange lands. We are hearing nowadays of the exchange of instructors between the great universities of America and Europe. The dream for secondary schools is but a step farther. If such things could creep down from the colleges and universities as rapidly as have football, fraternities, college yells, and college rowdyism, it certainly would not take long for an international exchange of instructors to descend to the secondary schools.

5 It is more than a duty. It is a privilege. It offers that opportunity for investigation so much desired by many secondary school instructors and so often urged by the University Professor. The investigator's attitude of mind in the teacher changes the whole aspect of school room problems. It may even make the reading of papers a pleasure. Mistakes, before a vexation, now are items of interest because they show how the studen 's mind is working. It gives the teacher an appreciation of the personality of the individual student that is a pleasure and a never-ending source of interest, and results in bringing student and teacher nearer together, for there is nothing to which the student is so sensitive as to the real feeling of the instructor toward him. The instructor is thus placed in a position of advantage in discovering the hopes and ambitions that lie deeply concealed in the heart of the student. When these things are known the problem of satisfying the demand of the student or of stimulating in him demands that will result in his greatest growth may be attacked by the methods which the scientist is accustomed to use in the solution of his problems. Is it not a reflection on the scientific methods of the science teacher that so much time has been given to studying how to teach the subject and so little time has been given to studying what the nature of the student demands at the successive stages of his growth?

PHOSPHATES OF NORTHERN ARKANSAS.

An exhibit at the Louisiana Purchase Exposition in St. Louis that attracted a great deal of attention was a solid block of phosphate rock 4 feet wide, 8 feet long, and more than four feet high. It was exhibited by the Arkansas Fertilizer Company, the company operating the phosphate mines and the fertilizer plant on Lafferty Creek, Independence County, Ark. So many questions were asked about the deposit from which it came that Mr. A. H. Purdue of the United States Geological Survey, who had arranged for the exhibit, made a special trip to Arkansas last August for the purpose of studying the developed phosphate beds of that region. He afterward prepared a brief report on the subject will soon be published in the Survey's forthcoming volume "Contributions to Economic Geology, 1906."

The only point where the phosphate deposits of Arkansas are now worked is a quarry from one half to three fourths of a mile east of White River. These deposits have a wide east-west extent, reaching from the town of Hickory Valley, 10 miles northeast of Batesville, westward at least as far as the town of St. Joe in Searcy County, a distance of more than 80 miles on a direct line. While it is certain that prospecting for workable deposits throughout most of this distance would be useless, it can confidently be expected that other points than those now known will be discovered where the rock can be mined with profit. Especially is this true of the eastern part of the field.

The credit of the discovery of these deposits belongs to Dr. J. C. Branner, formerly State geologist of Arkansas. Many observers had noted them, but their true nature was not known until Dr. Branner in 1895 made analyses of the rock in the laboratory at Stanford University.

In June, 1900, a company was organized for the development of the phosphate beds along Lafferty Creek. A mining and milling plant was erected, which was later destroyed by fire. A much larger plant has recently been erected at Little Rock. It has an annual capacity of 40,000 tons with a shipping capacity of 15 to 18 cars a day.

The phosphate rock is of sedimentary origin. Where developed, it is light gray, homogeneous, and conglomeratic, the pebbles being the size of peas and smaller. There are two well-defined beds, but only the upper one is worked, the lower being considered too low in grade for further exploitation. The aggregate thickness of the two beds is from 8% to 10 feet.

The beds were probably put down near shore, as the sea advanced landward. Their phosphatic nature is thought to be due mainly to the organic fragments that constituted so large a portion of their mass, though it may be due in part to the droppings of marine animals.

Persons interested in fertilizers and the phosphate deposits of the country will find in Mr. Purdue's paper a description of the developed deposits of Arkansas with some discussion of the geology of the region.

THE RECESSION OF NIAGARA FALLS.

Probably no one who has looked down on the falls of the Niagara River and the grand canyon they have carved for themselves out of the solid rock but has felt his brain oppressed with the idea of eternity and the incomprehensibility of it. It is a thought that will be driven home to those who may read the recent pamphlet of Mr. G. K. Gilbert of the United States Geological Survey concerning the rate of recession of Niagara Falls. Not only does he tell us that the great falls are not what they have been within the memory of man, and show us pictures and maps to prove that their outline has changed, but he gets out his tape line and measures the distance that they have receded within certain years.

The data for computing the rate of recession of Niagara Falls include surveys of the crest line made in 1842, 1875, 1886, 1890, and 1895, and cameralucida sketches made in 1827. During the period covered by these data the rate of recession has not differed to an important extent from the natural conditions. The present and prospective diversions of water for economic uses interfere with the course of nature and may be expected to modify the rate of recession.

The rate of recession of the Horseshoe Fall, or the rate of lengthening of the Niagara gorge, during the sixty-three years from 1842 to 1905 is found to be five feet per annum, with an uncertainty of one foot. For the thirty-three years from 1842 to 1875 the rate was apparently slower than for the thirty years from 1875 to 1905. The rate of recession of the American Fall during the seventy-eight years from 1827 to 1905 was less than three inches per annum.

The time consumed in the recession of the falls from the escarpment at Lewiston to their present position, or the age of the river, is not here estimated. It can not properly be computed without taking account of all conditions, local and temporary, affecting the rate of recession, and some of those conditions have varied greatly from point to point and from time to time.

Mr. Gilbert's report is published as Bulletin No. 306 of the Geological Survey. It is accompanied by a report on the survey of the crest line of Niagara Falls by Mr. W. Carvel Hall, who made the survey in June, 1905. The work was done under a plan of coöperation between the Survey and Mr. Henry A. Van Alstyne, State engineer of New York. Mr. Hall adds two tables to his report, one showing the artificial monuments and other permanent reference points connected with the triangulation of the surveys, the other the distance between permanent reference points.

COVE CREEK SULPHUR BEDS, UTAH.

A glimpse of Hades itself-and what is worse the smell of it-may be obtained at Sulphurdale, Utah, where sulphur is apparently in process of formation and concentration. Here and at several other localities in the neighborhood are valuable deposits of sulphur, which

have attracted the attention of Mr. Willis T. Lee of the United States Geological Survey, who has recently visited them and now describes them in the Survey's forthcoming volume "Contributions to Economic Geology, 1906.”

Sulphurdale is a small mining camp about twenty miles north of Beaver, Utah, the nearest town of any considerable size. The deposits, which are owned by the Utah Sulphur Company of Salt Lake City, are situated about four miles south of the site of old Cove Fort, and are locally known as the Cove Creek sulphur beds. Cove Creek sulphur has supplied the local market for about thirty years, the average annual output being estimated at one thousand tons. An area of several acres has been exploited, but the lateral extent as well as the depth of the deposits is unknown.

Some of the sulphur occurs in cylindrical masses or cores ten or fifteen feet in diameter, having a rude radial structure as if they had been formed about a central vent extending indefinitely downward into beds of tuff. But it occurs mainly as a dark-colored impregnation or cementing substance in the rhyolitic tuff. In certain places it appears as irregular veins of nearly pure yellow sulphur ramifying through the beds. Occasionally a smaller cavity is found lined either with flowers of sulphur or with sulphur crystals.

This sulphur is probably the result of volcanic action, as shown by its presence in a volcanic region where recent eruptions have occurred. Gas is escaping in large volumes, in some areas by thousands of small jets from the porous beds of tuff. Wherever water is found standing in the excavations, the gas is noted boiling up through it at short intervals. The disagreeable odor of hydrogen sulphide is strong, and it is probable that this gas is the origin of the sulphur, the hydrogen in the gas uniting with the oxygen in the porus tuff to form water, and leaving the sulphur behind as a solid.

The ore varies in richness from a trace to practically pure sulphur. Samples taken at the extremities of the workings and analyzed in the laboratory of the Geological Survey were found to contain respectively eighty per cent and sixty-five per cent of sulphur. Material running as low as fifteen per cent sulphur is considered paying ore.

At the smelter, the ore is placed in iron retorts and the sulphur is melted out by steam. Analysis of the product, as it comes from the retorts, shows that it contains 99.71 per cent sulphur, .23 per cent non volatile residue, and .06 per cent of moisture.

ARTICLES IN CURRENT MAGAZINES.

Forestry and Irrigation for April: "Forestry in the Middle West," "National Forests at Close Range." "Fish and Irrigation Ditches," "Wood Paving," "United States Timber Supply," "Millions for Moisture." "Senate Debate on National Forest Policy," "Improving the National Forests.”

Popular Science Monthly for April: "Pioneers of Science in America," with portraits: "Notes on Development of Telephone Service," Fred DeLand: "The General Economic Importance of Mosquitoes," Professor John B. Smith; "The Value of Science," M. H. Poincaré; "The Reclamation of the North Platte Valley," W. S. Coulter; "How Shall the Destructive Tendencies of Modern Life be Met and Overcome?" Dr. Richard Cole Newton.