THE TOWER FOUNDATION SEPT. 19, 1906 



exercise of greater discretion in the selection of the 

 various subcontractors, than would have been pos- 

 sible under a general contract. It thus resulted in 

 obtaining the best possible workmanship and material 

 throughout. There were more than one hundred 

 different contracts. 



The plans for the Bourne Building Addition were 

 filed with the Municipal Bureau of Buildings on 

 April 19, 1906, and approved one month later. 

 After the estimates had been taken, various contracts 

 let and the old buildings demolished, the architect's 

 superintendent took possession of the site on June 

 16, 1906, began excavating on the 22d, started the 

 reenforced concrete foundation on July 16th, and 

 the structural iron work on Aug. 7, 1906. 



The plans for the Tower were filed June 29th and 

 passed Sept. 12, 1906. 



On Sept. 19, 1906, work was begun by running 

 a steamline from the old building, for operating the 

 air compressor to be used in connection with the 

 sinking of the foundation caissons. On the same 

 day the derricks and hoisting machines were set up 

 and the needling of the adjoining building begun. 



On Sept. 24th the excavations were started; on 

 Oct. 1st the material for the first caisson delivered, 

 and on Oct. 25th concreting was begun in the first 



[11 



caisson, after it had landed at the level, 84 feet, 4 

 inches below the curb. 



The steel work was started on November 20, 1906, 

 by setting the grillage for columns 31 and 32. 



The plans for the Singer Extension were filed 

 Dec. 26, 1906, and those for the Bourne Building 

 Alteration, March 27, 1907. 



The last foundation caisson for the Tower was 

 landed Feb. 18, 1907, at level 87 feet, 7 inches 

 below the curb. 



From that time .on the operations proceeded with- 

 out interruption, there being often over 1,200 men 

 employed daily. The building was practically com- 

 pleted on May 1, 1908, or only one year and eight 

 months after the start. 



Compare this with the time it took to erect the 

 Cologne Cathedral, the twin towers of which are 

 surpassed by the Singer Building in height. The 

 Cathedral was begun in 1248 and finished 641 years 

 later in 1889. 



A comparison might also be made, with the great 

 pyramid of Cheops, on which 100,000 men were em- 

 ployed for 30 years, which would be equivalent to 

 3,000,000 men working every day for one year as 

 against 1,200 men employed every day for one year 

 and eight months on the Singer Building. 



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