difficult ford. The bridge was built entirely from timber hewn on the ground. It is 117 feet long, in three spans, with 12 by 12 inch stringers, five to each span. The clear roadway is 14 feet 4 inches. The abutments are 18 feet long, drifted into the bank with 18-foot logs. The piers are 18 by 7 feet, pointed on the upstream ends. All parts of the piers and abutments are thoroughly drifted together, and the interiors are completely filled with rock. The floor is made of split logs 8 to 10 inches in diameter, adzed off to make a level roadway. This work was completed on the 28th of July. Three illustrations1 of the completed work accompany this report.

In order to secure a good location for this bridge it was necessary to move upstream from the ford 3,500 feet and to build in all something over 4 miles of new road. This work was done while the bridge was being built.

The rest of the work during the season consisted in completing and repairing the road as previously built. This work was carried over the entire length except about 3 miles at the east end, which will probably be abandoned in favor of a new location. An important feature of this work was the cutting out of a bad hill near the western end of the road, in the vicinity of what is called the "Joe Smith Ranch." This was an exceptional case where cutting out a hill shortened the road. The distance gained was about 1,200 feet, and the very heavy grades were entirely removed.

The work of the party was suspended on the 13th of September and the return to Mammoth Hot Springs was begun.

During the month of October Mr. S. F. Crecelius and Foremen F. L. Walker made a reconnaissance along the Wind River Valley to determine the best location of the road over the remainder of the distance to Fort Washakie, in case further appropriations were made for the work. Mr. Crecelius was also instructed to look into the matter of unauthorized changes of the existing road by private parties. The report of his reconnaissance is appended.1

The entire line of the military road from Fort Washakie to Jackson Lake was examined by the officer in charge between August 26 and August 27, 1900.

The balance of the appropriation still remaining in hand will be expended during the ensuing season.

Some criticism has been made of the location of that portion of the military road between Fort Washakie and Jackson Lake which was built in 1898, but this has arisen from an entire ignorance of the purposes for, and conditions under, which the work was done. The sum available was only $10,000. The distance from a base of supplies was on the average 125 miles. The length of road to be opened was 53.8 miles, and the time in which to organize a force and do the work only about two months. To locate and build the road as those are built in the Park would require at least $100,000. It was therefore an imperative necessity to disregard the best location and go where a road could be opened with the least work. The feat of getting through at all was a most creditable one, and the fact that the location is not what a thorough survey and ample funds for construction would have determined should not detract from it in the least.

1 Not printed.

APPENDIX JJJ.

ERECTION OF A MONUMENT TO SERGEANT CHARLES FLOYD.

REPORT OF CAPT. H. M. CHITTENDEN, CORPS OF ENGINEERS, OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1901.

UNITED STATES ENGINEER OFFICE,

Sioux City, Iowa, June 30, 1901.

GENERAL: I have the honor to submit herewith my annual report for the fiscal year ending June 30, 1901, upon the erection of a monument to the memory of Sergeant Charles Floyd. It is also a final report, the work having been completed and all the accounts closed. Very respectfully, your obedient servant,

H. M. CHITTENDEN, Captain, Corps of Engineers, U. S. A.

Brig. Gen. GEORGE L. GILLESPIE,

Chief of Engineers, U. S. A.

REPORT ON ERECTION OF A MONUMENT TO SERGEANT CHARLES FLOYD.

Owing to the small amount of funds available for this work and the character of the situation where the monument was to stand, it was considered that a plain shaft would produce the best result that could be expected. The design selected was that of the Egyptian obelisk and its dimensions were to be controlled by the capacity of the funds to do the necessary work. In fixing upon the proportions for the monument the dimensions of existing ancient examples were carefully studied to determine if possible the rule followed in these works. The three elements upon which the form and appearance of an obelisk depend are (1) the ratio, r, of the total height, h, to the side of the base, b; (2) the ratio of the side of the top of the main shaft to that of the base; (3) the ratio of the height of the pyramidion to the side of the base of the shaft. In regard to (2) and (3) there is much uniformity in the classic models, though by no means absolute. The value of (2) is approximately two-thirds and that of (3) is approximately unity-that is, the side of the top of the main shaft is two-thirds that of the base, and the height of the pyramidion is equal to the side of the base. The value of (1) is exceedingly variable and in twenty-one examples of the larger obelisks, whose dimensions are given by Gorringer, it ranges from 7.9 to 12.5. No definite relation seems to exist

between this ratio and the height of the obelisk except that on the whole it increases with the height. This would in fact naturally result from the requirements of stability, for, with the same material and wind pressure, the higher the monument the smaller may be the base in proportion to the height.'

Apart from these theoretical considerations, the results of experience seem to indicate that a height ranging from ten to twelve times the base gives a more satisfactory artistic effect than any smaller value. How far the appearance of a monument may be injured by disregarding these classic proportions may be seen in the three examples in the accompanying cut which are all reduced to the same height. They are the Washington Monument, the highest in the world; the Bennington Battle Monument, second highest in the United States; and the Bunker Hill Monument. Their heights in full numbers are respectively 555 feet, 306 feet, and 221 feet. In the Washington Monument = 10, and the base and height of pyramidion = b and b respectively. The proportions have been universally recognized as satisfactory. In the Bennington monument = 8.3, and there is no pyramidion, the lines of the main shaft gradually curving off from middle height to a point at the apex. In the Bunker Hill Monument = 7.4 and the base and height of pryamidion seem to be the same and each equal to b. The difference of appearance in these three examples is very marked and wholly to the advantage of the Washington Monument.

In regard to wind pressure it is a common practice to assume a force of 50 pounds per square foot as an absolutely safe allowance. Undoubtedly, in the case of an obelisk, this is larger than is is necessary. While actual pressures as great as this have been recorded on small surfaces, it is very doubtful if they are ever developed simul

side of main shaft at top.

wind pressure in pounds per square foot.

Let w average weight of the monument per cubic foot of volume within the exterior lines.

Let the condition of stability be such that the line of resultant pressure from pand w shall fall at the limit of the middle third of the base-that is, that the factor of safety against overturning shall be three. The following formula will then result:

Knowing the value of w and assuming a value for p, the proportion and size of a monument for any desired height directly results. Upon the accompanying diagram are curves for h and b corresponding to w = 145 and p 40. By means of the rules printed on the diagram the values of h and b corresponding to any other assumed values of w and p can be readily determined. The curves show that the ratio r increases with h.

While the above equation will give the true economic relation between the base and height of an obelisk within all practicable limits of weight and wind pressure, and for an ample factor of safety against overturning, it is not likely that for the higher obelisks it would give the most desirable result from an artistic point of view. For an obelisk of the height of the Washington Monument it is evident that a much more slender structure would have ample stability, but whether it would produce as satisfactory an effect is difficult to say in the absence of any actual example. There is another element that might also enter if it were attempted to erect a very high structure on these strictly theoretical proportions. It might be found that the weight of the shaft would produce a pressure per square foot at the base beyond the safe resisting power of the rock. On the other hand, the total weight being less, a smaller and less expensive foundation would be required.