148 



SCIENCE 



[Voi,. V., No. 107. 



in 1853, ' There is no perceptible settlement' 

 of the base, — a statement which seems hardly 

 accurate, judging from what is usual, and from 

 what appeared later. Here may be mentioned, 

 as of interest later, that the architect, Mr. 

 Mills, in 1848, levelled from the top of the 

 third course or step of the foundation to a point 

 on top of the meridian-stone monument near 

 tide-water, planted by President Jefferson, and 

 thus established a reference by which he might 

 detect any settlement occurring in the progress 

 of the work. 



On Feb. 22, 1855, congress having been 

 petitioned for aid, a committee of the house 

 approved of the work done, and recommended 

 an appropriation of $200,000. But this was 

 the period of the Know-nothing excitement ; 

 and, on the ver} T day that the appropriation 

 was recommended, the books and papers of 

 the monument society were forcibly seized by 

 adherents of the American party, and a new 

 board was illegally formed from their members. 

 This action again delayed progress, and, dur- 

 ing their rule of four years, only four feet were 

 added, bringing the obelisk to the height of 

 156 feet above the base, at which elevation 

 it long rested. On Feb. 22, 1859, this board 

 was ousted by the incorporation by congress 

 of a new Washington monument societ} 7 for 

 the purpose of finishing the work. These 

 changes probably account for the more or less 

 complete disappearance of the original plans, 

 measurements, bench-marks, etc., which is 

 afterwards noted. The civil war soon followed, 

 and no actual work was done for many years. 

 The societ} T remained as custodian during this 

 time, and made some attempts to re-awaken 

 public interest. Numerous examinations were 

 made b} T government officials of the condition 

 of the stone work, which in some places was 

 slightly chipped at the edges b} T flush jointing, 

 and of the foundation. In April, 1874, Lieut. 

 Marshall found that the axis of the shaft was 

 inclined 1.4 inches to the north-west. At one 

 time it was hoped that the bare shaft might be 

 finished in some form by July 4, 1876 ; but 

 the unsatisfactory condition of the foundation 

 prevented. 



All hope of completing the monument by 

 the centennial anniversary having gone, the 

 matter apparently rested until August, 1876, 

 when an act of congress was approved, pro- 

 viding that there should be appropriated $200,- 

 000 in four annual instalments, to continue 

 construction ; the officers of the societ} 7 being 

 required to transfer the proper t} 7 to the United 

 States, and the construction of the monument 

 to be under the direction of the president of 



the United States, the supervising architects 

 of the treasur} 7 and of the capitol, the chief of 

 engineers, and the first vice-president of the 

 monument society. In the examination called 

 for in this act, it was very curiously discovered, 

 by levels taken to what was then supposed to 

 be the meridian-stone previously referred to, 

 that the monument had, in twenty-eight years, 

 settled nearly nine inches into the ground. A 

 livery investigation by those most interested 

 presently developed the fact that Gen. Bab- 

 cock, when in charge of buildings and grounds 

 in Washington, had, in the course of improve- 

 ments, graded off and carted away the merid- 

 ian-stone monument ; so that, added to the 

 loss of all plans and details, we must now 

 relinquish all hope of knowing whether the 

 monument had settled or not. 



Congress then authorized the re-enforcing of 

 the foundation ; and the work was placed in 

 charge of Lieut. -Col. Thomas Lincoln Casey, 

 U.S. engineers, who had devised, and has suc- 

 cessfully carried out, the plan shown in the 

 sketch. The earth about the base, some 10,- 

 000 cubic yards, was first removed. Then a 

 trench 4 feet wide, 13.5 feet deep, extending 

 23 feet outside of the old foundation, and tun- 

 nelling 18 feet under it, was excavated. The 

 trench was then filled with concrete of four 

 parts broken stone, three parts pebbles, two 

 parts sand, and one part Portland cement, 

 mixed by machinery in a cubical box rotating 

 on a diagonal axis, and then thoroughly rammed 

 in place. When the space under the old foun- 

 dation was as nearly filled as convenient, more 

 concrete was put into small gunny-sacks, and 

 rammed home horizontally, while } T et soft, 

 with a heavy timber. The order in which 

 these trenches were made and filled is num- 

 bered on the plan. At first it was intended to 

 make and fill two opposite trenches at the 

 same time ; but it was found that removing 

 144 square feet of the foundation (only 2.5 %) 

 caused a too rapid motion of the column, and, 

 after the first four trenches, but one trench 

 was made and filled at a time. This sensi- 

 tiveness of the obelisk to disturbance appears 

 to confirm the opinion that the old foundation 

 Was alread} 7 carrying nearly the maximum 

 allowable load. 



The effect of cutting these trenches was 

 studied by means of a plumb-line suspended 

 from the top of the shaft, and hanging freely 

 through a graduated metal circle near the 

 floor. The greatest movement at the begin- 

 ning of the work was \\ of an inch. By 

 careful watching and working, the original 

 deflection of 1.75 inches was almost entirely 



