Five-mile line.-The geodetic coordinates were determined for Canal Zone boundary monuments as follows: No. 139 A Dolores; No. 'S 53, 53, 54, and 541 A Chilibre; No. 35 A Lindero; No. 16 A Zorra; No. 'S 154, 155 A Canito.

JOINT LAND COMMISSION.

Surveys were made and maps prepared showing boundary lines, areas, and improvements on various estates as follows:

Venada Island.-Geodetic position, shore outline, topography, and area at mean high spring tide.

San Lazaro.-Area redetermined.

Mandinga Pihisba.-Two maps prepared, one showing only the boundary lines and areas of the Mandinga and Pihisba estates and the other showing in addition the boundary lines and areas of the following conflicting estates: Agua Sucia, Cuatro Caminos, Oces, and El Calvario.

Punta Mala.-Survey of the playa made, locating the 21-foot contour. Tracings and photographs of old French maps were made. A compromise area of the property was consummated.

Arcia Bracho.-This line was established by the placing of five pipe and concrete monuments.

Ensenada de las Minas.-A search was made for a stone monument at the headwaters of the Rio Palo Canoa on the boundary of this estate.

Majagual.-A survey was made of a cane field near Majagual.

Alba. The areas were determined for two strips of high ground on each side of the mouth of Farfan River, also the area of the remainder of the high ground in this vicinity and to the west of the river.

Alba Guayabal.-Testimony was given before the Joint Land Commission on these two estates.

Flooded land.-An investigation trip was made to the vicinity of Santa Rita in connection with a portion of the flooded area of Gatun Lake.

SUPPLY DEPARTMENT.

Pastures. Surveys were made and maps prepared showing the boundary lines, areas, roads, trails, fences, etc., on the following pastures: Empire, Gorgona, Pedro Miguel, Mount Hope, and Monte Lirio.

A tracing was made of the land defense maps showing the watercourses over the Mount Hope area. Tracings were also made showing the watercourses from the following sheets: Panama, Miraflores, Pina, and Gatun.

Plantations.-Surveys were made, maps prepared, and areas determined for the Chagres River plantations as follows: Limon, 227 acres; Las Guacas, 169; Gatuncillo, 62; Chilibre, 59.2; Palenque, 25; Rio Hondo, 15; Juan Mina, 47.

CRISTOBAL COALING PLANT.

Spread of piers.—In September and October, 1916, the width between the bridge tracks on the two piers was measured at 12 sections and it was found that the width had increased by one-fourth inch at the most troublesome section and by a maximum of one-half inch at 1,500 feet from the south end, in comparison with the measured width of November and December, 1915, the latter being about one-fourth inch greater than the theoretical span.

Monumented base lines were accordingly established with reference to the center lines of the bridge tracks and measurements were taken twice in November and December, once in January, and thereafter every other month. All measurements to date show that no further movement is taking place.

Settlement of piers.-Relative elevations on the two piers were taken, and profiles drawn up showing the maximum, minimum, and average difference of elevation between the two piers along the center lines of the bridge tracks.

Bridges.-Investigation was made of the condition of the two reclaiming bridges and the found data submitted in the form of sketches showing, first, the positions of the pins and tops of girder columns with reference to the center line of tracks, developing the maximum deviation; second, the tilt of trucks, developing the maximum deviation; third, the reduction of camber in the two bridges.

Unloader cranes.-Profiles were taken over the booms of the unloader cranes in the tests and the results forwarded to Mr. Duchscher.

SURVEY-PANAMA, ANCON, BALBOA.

The survey of the district is about 75 per cent complete. It was divided into 7 sections, over which were established 14 stations by precise triangulation, which, together with those previously established, made a total of 18 stations. Starting from these stations, the district was covered with a network of closed traverses, mostly by transit and steel tape, a few by transit and stadia. To date there are 414 traverse points whose geodetic coordinates and elevations (except 380-387) have been determined.

The scope of the survey is as follows: Panama, location of all important public and private buildings and Panama Railroad property lines; Canal Zone, location of all buildings and sidewalks; both Panama and the Canal Zone, location of street lines, railroads, manholes, fire hydrants, high and low water lines, streams, ponds, culverts, bridges, 5-foot contours up to the highest excavation level on Ancon Hill and just beyond building line on Sosa Hill, and thence 10foot contours.

In addition, work is being done for the electrical division as follows: Location of man and pull holes, street lights, and transformer houses.

Two methods have been used: First, the plane table; second, the modified plane table or transit and stadia and field-drafting board. The latter method is found to be more satisfactory. The present status of the survey by sheets is as follows: One to four, inclusive, 90 per cent complete; 5-6, map projection only; 7,80 per cent complete. The finished map will be in two sections on a scale of 1:2,000.

GENERAL SURVEYS.

Coco Solo submarine and aviation base.-A survey was made locating and monumenting the boundary lines of the Coco Solo base. The boundaries are fixed by three concrete monuments. A map was prepared and a description by metes and bounds drawn up.

Military trails.-Land-defense trails were cleared as follows: Main PinaGatun trail from the west end of Gatun dam to the Rio Pina, about threefourths of a mile upstream from the village of Pina, 12.90 miles; Pina Branch trail across the Rio del Media, including the construction of a 30-foot span packmule bridge across the Que Pedro, 1.50 miles; Indio Ridge trail, from A Burn to the coast, about one-half mile northeast of the village of Pina, 13.88 miles; Indio Low trail, from the borrow pit across the Rio Indio and joining the Indio Ridge trail about 1 mile at right angles to the east of the Zone line, including the construction of two pack-mule bridges, 3.50 miles; Indio Branch trail from A Cedar to A Muru, 0.69 mile; Lake Shore trail from A Pina, past A Bruja, to a junction with the Pina-Gatun trail, including branches to landings, 4.06 miles; Miraflores trail, 2.95 miles; Miraflores highway trail, 4.85 miles; Pedro Miguel trail, 1.80 miles; Pedro Miguel highway trail, 6.08 miles. All trails were cleared approximately 20 feet wide except the Miraflores and Pedro Miguel highway trails, which were cleared 40 feet wide. Total, 41 28 miles of 20-foot trail and 10.93 miles of 40-foot trail.

Pacific terminals.—In order to keep a line on the lateral movements of the unloader and reloader wharves of the coal pocket, the quay walls, docks, head walls, and piers, the old test lines were extended and tied in, and where necessary fixed with permanent foresights. The first investigation was completed in January, and the data were tabulated and shown by diagrams on a large tracing. The results obtained indicated the necessity of a check not oftener than once in six months.

Colon radio reservation.-A survey was made of the new boundary lines of the Colon radio reservation, a map prepared, and a description by metes and bounds drawn up. Concrete monuments have been set at some of the corners and their geodetic coordinates determined.

Quarantine hospital reservation.-A survey was made locating the proposed new boundary lines of the quarantine reservation and the present lines of the hospital reservation, with the view of monumenting the whole section in one piece. A map was prepared showing the proposed lines, and arrangements are made for setting the monuments at the completion of the fill now being made in this vicinity.

MISCELLANEOUS.

Royal Mail dock.-A survey and map were made of the Royal Mail dock in Colon.

Fuel-oil farms.-Stadia survey made, locating oil-pipe lines and fence lines on both the Atlantic and Pacific farms, and also locating the water-pipe lines on the Atlantic farm.

Transmission towers settlement.-A closed circuit of Y levels was run over the transmission line towers between Balboa and Diablo Hill for settlement in September and May.

Miraflores steam plant.-Elevations were established for various points at the Miraflores steam plant under the direction of the electrical division.

Hydrographic tower, Cristobal.—A true azimuth line was carried over from old wireless tower No. 2, and a true north and south line established by tacks set in the platform of the tower.

Submarine power cable.-A survey was made in connection with relaying a part of the submarine power cable to Toro Point. The spar buoys for marking the location of the cable across Limon Bay were located by intersectious and a map prepared showing the data necessary for picking up the cable at a future time.

Machine lathe, Balboa.-Lines and grades were given to a high degree of accuracy for placing the 65-foot turning lathe in building No. 1, Balboa shops. Breakwater.-Cross sections were taken every 50 feet on both the east and west breakwater, the sections plotted and traced.

Examination. An examination for levelmen and transit men was given on September 24.

Balboa dry docks.-Assistance was rendered in making the pump tests at the Balboa dry docks.

Area canal channel.-The area of the canal channel from the locks to the coasts at both ends was found to be 0.85 square mile.

Odd jobs.-Tests were made of 24 transits, 1 theodolyte, 12 levels, and 1 plane table for points of design and construction as follows: Clear aperture, aberration, magnifying power, objective slide, definition, flatness and size of field of view, sensitiveness of the telescope and plate bubbles, eccentricity of centers and verniers, and fineness of cross hairs.

The stadia interval was determined for three transits and one plane table. A boathouse was built at Gamboa and runways constructed to the water. Two cayucas were repaired.

In settlement of a controversy, the amount of coal delivered by the Panama Railroad Company into the bunkers of Pinel Bros.' steamer Panama was measured.

Assistance was rendered in computing excavation yardage on the Mount Hope and Diablo Hill borrow pits and in giving intersections for driving piles for the construction of the launch landing at Cristobal.

Maps. A tracing was made for the Panama Government showing the 100foot contours and shore lines and the monuments in the Rio Trinidad Valley; the 100-foot contour survey corrections were plotted onto the 1:20,000 map, also topography from the land-defense maps; a new tracing was made of the triangulation station data; the 5-mile Zone line was plotted onto the HarrisonArosemena map.

Miles of line.-Transit, 71.28; Y level, 290.05; precise level, 2.37; stadia traverse 130.77; side shots, 154; pocket compass, 19.49; trail and trocha, 113.5; total miles of line, 781.86.

SECTION OF OFFICE ENGINEER.

This section has continued with the preparation and production of all construction plans for the building division, electrical division, locks' division, municipal division, and the terminal construction work on the Atlantic and Pacific coaling plants and dry dock No. 1. This section has also handled the miscellaneous drafting work required from time to time by other departments and divisions of the canal.

The details of the work accomplished and of the force employed are given in the report of the office engineer, which follows:

SECTION OF OFFICE ENGINEER.

C. J. Embree, Office Engineer.

During the year we have had an average of 32 draftsmen in this organization, an average of 3 men being on leave, leaving an active drafting force of about 29 men, the majority of whom were engaged upon work for the building division.

The number of drawings issued and assigned vault file numbers during the year is as follows:

We have drawn drafting-room supplies from the storehouse in the amount of $847.40, an average of 15.22 cents per man per working day during the year, these supplies including tracing cloth, tracing paper, pencils, ink, etc.

We have issued all blue prints, white prints, and vandyke negatives required by the various divisions of the canal connected with this office, the total quantities produced and issued being as follows:

Blue prints.

White prints

Vandyke negatives....

Square feet.

265, 500 25, 300 12,000

It is estimated that there is a 10 per cent loss of paper, and that vandykenegative prints take five times the labor required to produce blue prints. Upon this basis our prints have cost us as follows:

This office has continued to issue specifications and requisitions for all spare and maintenance parts for the lock machinery and equipment, as well as maintaining an index to all such parts being held in stock.

TERMINAL CONSTRUCTION WORK.

ATLANTIC DOCKS.

T. B. Monniche, Engineer of Docks.

The work performed by the division of the engineer of docks during the fiscal year 1916-17, including both design and eonstruction work, was continued under the supervision of Mr. T. B. Monniche, engineer of docks, assisted in office work and preparation of plans by Mr. F. W. Blackwood, assistant engineer, and Mr. W. G. True, junior engineer, with the necessary clerks and draftsmen; also by Mr. C. A. Nelson, supervisor, who was in immediate charge of all construction work.

12406-17- -8

PIER No. 7.

At the close of the fiscal year ending June 30, 1916, all work had been completed on the substructure of Pier No. 7, while on the floor the only work unfinished was the laying of paving brick, which was 20 per cent complete. The structural steel for the shed had been 95 per cent completed, and the concreting of the walls and columns 20 per cent completed. During July, August, September, and October of the fiscal year 1917 all work remaining to be done on Pier No. 7 was completed with the exception of the erection of the bronze grill work over the doors at both ends of the building. This work was not completed until February, 1917, due to the contractor's failure to deliver all material until the end of January, 1917.

Shed. The erection of 4,410,672 pounds of structural steel for the shed was completed on September 30, 1916. This steel was furnished by Milliken Bros., of New York, at a contract price of $0.02309 per pound, amounting to a total of $101,842.42, delivered at Cristobal.

Regarding the erection of the shed steel it was decided to allow local contractors to bid on this work, together with the superintendent of erection of The Panama Canal, who bid on the part of the Government. Mr. J. O. Childers was the only contractor to bid, and his bid was for $10 per ton, whereas the bid of the superintendent of erection was only $7.50 per ton. In view of this the work was performed by the erection forces of the canal. The actual cost of the erection was $32,078.23, or approximately $14.58 per ton. This high cost was partially due to the slow delivery of steel from the States, which made it impracticable to put a full force of men on the work until several months after the first delivery of steel had been received. The total cost of the steel shed in place, including all charges from other divisions as well as work and material performed by the division of engineer of docks, was $159,934.77 for the total weight of 2,207

tons.

Cement roofing tile. The laying of tile by the American Cement Tile Manufacturing Company was started on June 7, 1916, and completed on September 19, 1916, 168 squares, or 10 per cent of the total, being erected during the fiscal year 1915-16 and the remainder of the total of 1,701 squares during the fiscal year 1916-17.

The cement tile for Pier No. 7 was manufactured on the Isthmus by the above-mentioned company in connection with the manufacture of 1,121 squares of tiling by the same company for buildings other than Pier No. 7.

The contractor was paid approximately $30,600 for the 1,701 squares of tiling erected on Pier No. 7, including the contract price of $3 per square for erection only.

Steel doors.-The type of doors adopted on Pier No. 7 was that furnished by the J. Edward Ogden Company, of New York. A total of 80 large doors were used as side doors, two doors divided by a swinging column being used at each 45-foot opening. At each end of the building one small door of the same type as the large doors was used.

The contract price for the doors completely erected was $71,988.80. The assembling and erection of the doors started on May 22, 1917, and was completed on September 25, 1917.