and a concrete backing of mansard slating were placed upon the long curtains, and similar work for the center pavilion was done in November. In conjunction with the roof-plastering, galvanized sheet-iron standingribs were embedded and secured to the iron rafters for the attachment of a copper roof-covering. Considerable delay was experienced in obtaining slates for the center and small pavilion roofs, owing to the necessity of using a quality and color that would match those of the completed south wing, and to accidents at the works of the manufacturer. Slating was, however, begun on the 20th of September, and continued, with numerous interruptions, until it was finally completed, January 7. On the 1st of October the roof-covering of 14-ounce sheet-copper was commenced, following the construction of the roof until the coppering was completed, about the 15th of January. The iron-work of the roof was painted as rapidly as the weather would permit during the winter and finished on March 1, while all the skylights were glazed with heavy, rough plate-glass in the latter part of December and finished on the 27th of that month.

FRONT AREA WALLS.

A change in the height of the front area walls, built with the main walls of the building, was required to preserve uniformity with corresponding walls and a like change previously made on the south front. This work, which consisted in the removal of the two upper courses of ashler and resetting the coping, was accomplished during the fall. The stones removed will be used in the area walls of the court-yard. At the same time the front areas were paved with brick.

CAST-IRON WINDOW AND DOOR FRAMES, TRIMMINGS, &C.

In the autumn of last year the roof was so far completed that the setting of the interior cast-iron door and window frames and trimmings might have been commenced but for the low state of funds. A contract could not be made to cover more than two-thirds of the work. In the hope of an appropriation from the extra session of Congress, expected to begin October 15, a clause was inserted in the specification furnished to bidders for a part of this iron work, reserving the right to include the whole building pro rata in the contract. A timely appropriation enabled such a complete contract to be made, and under it the work of supplying and erecting in place some 500 tons of this ornamental cast-iron work has been in steady progress ever since. The first load of iron arrived December 24, and its erection began January 19. At the close of the fiscal year this work is nearly completed in the attics, fourth and second stories, well advanced in the third and first stories, and begun on the court-yard side of the basement story. Some skirting for the attics has arrived ready to go into place.

STONE STAIRWAYS.

Before the close of the last fiscal year a contract was awarded for furnishing the cut granite for the two grand stairways, of six flights each, in the center pavilion, leading from the sub-basement to the attic, or fifth floor. Owing to a misapprehension on the part of the contractor as to the extent and difficulty of such a piece of work, in which no two steps of a flight could be precisely alike, besides differences between several of the flights themselves, a tedious and unexpected delay attended the whole work. Immediately upon the arrival of the stone

for the north stairway the setting of that stairway was commenced December 18 and completed March 30.

Each step of the geometrical flights was let into the wall 14 to 16 inches and firmly wedged, becoming virtually a cantilever.

Stone for the south stairway did not arrive until May 27. The setting of this was begun at the sub-basement floor on June 10, and has now advanced to include a part of the first story and the platform stones of all the landings.

It should be stated that all fitting of platform stones around columns and over beams and girders had to be performed at the building. It was a slow and delicate work.

HEATING APPARATUS.

On July 18 it was decided that the required extensive heating apparatus for this wing should be upon the hot-water system, similar to that used in the south wing, and that it should be constructed by day labor, employed directly by the government, the materials, boilers, fittings, &c., to be purchased by contract. The work included the steam boilers and pumps needed for the hot and cold water supply, and to furnish power for the elevators.

In November the study and drawings were finished for the whole apparatus, including the co-ordinate subject of ventilation adapted to the existing arrangement of flues.

Specifications and schedules of four separate classes of work, namely, boilers, flange-pipe, coils and fittings, and wrought-iron pipe, were at once prepared and published. Contracts were awarded and materials procured in season to begin work in the sub-basement on January 3, and to continue it vigorously without serious interruption to the present time.

On the 21st of May all the lower system of pipes, coils, boilers, &c., was in place, and the running of the suspended system commenced. At this date the work in the sub-basement is essentially completed, except placing and connecting the steam-boilers.

Most of the coils in the first story and many in the basement are set, and most of the flues for heating and ventilation have been provided with hoods and made ready for registers.

IRON-LATHED PARTITIONS AND OTHER IRON-LATHING.

On June 21, 1877, an arrangement of partitions and rooms suiting the requirements of the Navy Department was determined upon and adopted. It thus became necessary to subdivide nearly all the curtain rooms, of 90 feet 8 inches to 131 feet 9 inches in length, by means of light, fire-proof partitions. This was accomplished with 4-inch studs of braced 14-inch angleirons, and corrugated iron lathing laid in 3-inch perforated strips. These partitions, when plastered, are about 63 inches in thickness. They were erected under contract by the superficial foot, and are 73 in number, with an aggregate area on one side of 23,863 square feet. Their erection was commenced January 24, and completed, in connection with iron lathing below described, on May 6. All furring and lathing, wherever used in the building, is of iron of the same description as that of the partitions. It has been used to form grounds for some small attic cornices under mansard roofs, cornices in the two large center pavilion rooms of the third story, and in all cases for boxing girders, to form heavy architraves in the same room, and about the main stairways in

all the stories. With these exceptions little or no lathing is used in the building, plastering being rendered directly on the brick walls, and the cornices gauged on to corbel courses of brick.

WATER AND GAS SERVICE.

On the 30th of November the work of cleaning up the cellar or subbasement and other preparatory operations were commenced for the laying therein of the mains for the supply of water and gas. Connections between this system and the mains in Pennsylvania avenue were made by the United States for water, but by the Washington Gas-Light Company, as usual, for gas.

On December 8 the laying of a 12-inch water main was commenced from the 12-inch main in the avenue, down Executive avenue, 4 feet below grade, to the southeast corner of the approaches of the building, thence a 6-inch main westward, connecting with a 6-inch main in Seventeenth street. Four 8-inch fire-plugs were set on Executive avenue, an 8-inch outlet left opposite the center pavilion of the east wing, with which it was connected by an 8-inch pipe, and a like outlet left opposite the site of the east end pavilion of the north wing. These mains were completed and the water turned on December 24.

On December 27 the gas company began laying its main, and afterward deferred its full completion until the building materials piled in the . avenue could be removed. The water and gas mains were laid together in the main trench of the cellar, the former stopping there and being subsequently continued in connection with the heating apparatus, while the latter was extended in rising mains at each extremity of the wing, branching to each story. The gas piping of the building was completed and proved by the latter part of April, and the meter set on or about April 12.

DOORS AND WINDOW-SASH.

These are being made by hand on the ground in the most perfect manner of mahogany, excepting the doors of the lower part of the atticstory and of the sub-basement, which are of pine. The mahogany lumber arrived on February 4, immediately after which the manufacture was commenced with a greatly increased force, and has so continued to the present time. Work on the mahogany stair-rails was commenced on June 3, and will require some months for full completion.

FLOORING.

Throughout the building, all corridor and water-closet floors are to be tiled with marble; those of the low attic rooms will consist of concrete surfaced with Portland cement mortar, those of the cellar paved with brick, the floor of the library tiled, while all floors of rooms elsewhere will consist of 14-inch Southern pine boards laid directly upon concrete and nailed to 2 by 3 inch wooden sleepers imbedded in the concrete. Wroughtiron beams and brick arches leveled up with brick or concrete constitute the body of the flooring and render it fire-proof throughout the building. The laying of sleepers imbedded in concrete was commenced March 19, and has since been completed, save a few rooms in the basement required for workshops.

PLASTERING AND CORNICES.

The 50,503 square yards (plasterers' measurement) of plastering, 19,170 linear feet of ornamental cornice, and 16,400 linear feet of beam-molding in this wing is a work requiring for its proper execution about eight months' time. It will consume some 5,000 barrels of lime and plaster. The work was commenced on the 4th of April, and on the 1st of May

was well under way, since which time the force employed upon it has been rapidly increased to a total at present of 272 men. The first plastering was applied in the attic and fourth stories, and is being continued downward through the lower stories as rapidly as the cast-iron door and window work will admit. Sticking of ornaments on cornices was begun on June 3. The condition of the work at the present date is as follows: The roof of center pavilion is second-coated; attic story is finished, except white-coating walls; fourth story nearly completed, except whitecoating walls; second coat of second story is complete and cornices commenced; third and basement stories not yet begun.

IRON STAIRCASES IN ATTIC.

These are two in number, placed in rooms, one on either side of the center pavilion. Their construction, begun in February by the contractor, suffered much delay in his hands, and is not yet entirely finished. Their erection in the building was begun on April 12.

ORNAMENTS FOR THE THREE FRONT PEDIMENTS OF MANSARD ROOFS OF PAVILIONS.

Designs and models of these ornaments were made between August 15 and December 17, and a contract entered into for their construction in cast iron. At this date they are all practically completed and ready for their positions, in which they will shortly be placed.

ELEVATORS.

This wing will contain two elevators, one on either side of the center pavilion, and landing at every floor from the cellar to the attic inclusive. Designs for cars and apparatus for both have been determined upon, and a contract for their construction during the coming fall is ready for signature.

LOWERING DERRICKS.

Two of the four heavy boom-derricks employed in the erection of this wing were lowered from the roof to the ground early in August, and the remaining pair the last of October.

APPROACHES.

In the latter part of April all the surplus earth was removed and necessary excavations made for foundations of walls and establishment of grades for the approaches. About the same time all the curb-stone was cut and dressed, while a contractor was, and is still, actively preparing the stone required for walls, posts, and main entrance buttresses and steps. A partial shipment of this stone was lately received, and a number of stones upon the southerly sections have been set. Further operations await the balance of the stone from the contractor. It is expected to arrive in a few weeks.

LIBRARY.

On the 17th of July last the Secretary of the Navy decided that the large room comprising the fourth and attic stories of the center pavilion front should be used as a library, and desired that it be appropriately furnished as such. Designs and drawings for the work in iron are well advanced and parts of the modeling done.

COURT-YARD, AREA-WALLS, AND COAL-VAULTS.

The appropriations made at the close of the last session of Congress have enabled the necessary steps to be taken for the preparation of cut stone for the area-walls of the court-yards north and south. Plans are

already complete for the arrangement of these yards, including ample subterranean vaults for the storage of fuel for the several wings of the building. This naturally includes the area-wall and vaults for the south wing, which will be constructed by this office at the expense of appropriations available for that purpose.

AUCTION SALES OF STONE-CUTTING PROPERTY.

Under the previous system of fifteen per cent. contracts there had accumulated, by purchase, fabrication, &c., a large amount of property for the use of the contractor in cutting stone for the front walls of the superstructure of the building at Manchester, near Richmond, Va. This property consisted of shops, sheds, tools, patterns, gauges, &c., in short everything for the outfit and accommodation of three hundred stonecutters. Modifications in the contract for work done at this place, referred to in my last annual report, rendered this property of no further use to the United States, and it became advisable to dispose of the same according to law. It was, therefore, sold at public auction on the premises, after due advertisement, on July 25, 1877. The net proceeds of the sale, amounting to $4,753.56, was turned into the Treasury.

IN GENERAL.

It will be noted that the only wood or combustible material entering into the construction of this building is in the surfacing of Georgia pine, laid air-tight and closely matched upon the office floors only; in the doors, partly of white pine, but mainly of mahogany; in the interior casing and finish of water-closets and bath-rooms, chiefly with black walnut; and in the window-sash, of solid mahogany. All else consists of stone, brick, concrete, plaster, iron, copper, and glass.

The following table shows the contracts entered into and in force during the year for the east wing: