This contract was divided into two parts:  “Work In and Under Ninth Avenue” and “Work Between Ninth and Tenth Avenues,” and unit prices were quoted for the various classes of work in each of these divisions.  The prices quoted for excavation included placing the material on scows supplied by the Railroad Company at the pier at the foot of West 32d Street, on the North River; there was a clause in the contract, however, by which the contractor could be required to make complete disposal of all excavated material at an additional unit price, and this clause was enforced on January 1st, 1909, when about 94% of the excavation had been done.

For the purpose of disposing of the excavated material in the easterly portion of the Terminal, the New York Contracting Company-Pennsylvania Terminal had excavated under Ninth Avenue a cut which came to the grade of 32d Street about midway between Ninth and Tenth Avenues, and a trestle was constructed from this point over Tenth Avenue and thence to the disposal pier at the foot of West 32d Street.

On May 11th, 1906, the work of excavation was commenced on the east side of Ninth Avenue, and on July 9th, 1906, on the south side of 31st Street, between Ninth and Tenth Avenues.  From the beginning, the excavation was carried on by day and night shifts, except on Sundays and holidays, until January, 1909, except that during the period from November, 1907, to October, 1908, the night shift was discontinued.

Geology.—­The rock encountered may be classed as “gneiss”; its character varied from granite to mica schist.  It was made up of quartz, feldspar, and mica, and there were also some isolated specimens of pyrites, hornblend, tourmaline, and serpentine.  On the south side of the work, just west of Ninth Avenue, there were excellent examples of “contortions” of veins of quartz in the darker rock.  On the east side of Ninth Avenue, near the north end of the work, glacial marks were found on the rock surface.  The general direction of the stratification was north 5 deg. west, and the general incline about 60 deg. with the horizontal.  As a rule, the rock broke sharply along the line of stratification.  On the south side it broke better than on the north side, where it was usually softer and more likely to slide; and this, together with the fact that in winter it was subject to alternate freezing and thawing and in summer to the direct rays of the sun, made it rather difficult to get a good foundation for the retaining walls.

WORK IN AND UNDER NINTH AVENUE.

General Description.—­The work involved the excavation of about 375 ft. of the full width of Ninth Avenue to an average depth of about 58 ft., and the construction over this area of a steel viaduct, the deck of which was about 24 ft. below the surface, for the ultimate support of the Ninth Avenue structures.

The following estimated quantities appear in the contract:  Excavation of rock, 72,600 cu. yd.; excavation of all materials except rock, 9,300 cu. yd.; concrete (1:3:6) in abutments, etc., 1,680 cu. yd.; timber, 504,000 ft., B.M.; structural steel, 1,320,000 lb., etc.