LETTER OF TRANSMITTAL. To His Excellency Samuel W. Pennypacker, Governor of Pennsyl vania: Sir: The undersigned, appointed by you Commissioners of the Topographic and Geologic Survey of Pennsylvania, under Act of Assembly, approved May 11, 1905, have the honor to submit the fol lowing report of the results of the work. Harrisburg, Pa., July 2, 1906. Very respectfully, GEORGE W. McNEES, UNIVERSIT OF CALIFORNIA TOPOGRAPHIC AND GEOLOGIC SURVEY OF PENNSYLVANIA. MADE IN CO-OPERATION WITH THE UNITED STATES GEOLOGICAL SURVEY. The work being done under direction of this Commission was started under provision of the act approved April 28, 1899, (See Appendix A). The Commission appointed under that act entered into a contract with the Honorable Charles D. Walcott, Director of the United States Geological Survey, on July 12, 1899, under which contract, (see Appendix A), the United States Geological Survey undertook to do the work of preparing a topographic map of Pennsylvania, on a scale of 1:62,500, (approximately 1 mile per inch), with contours for every 20 feet of elevation, and in accordance with the act of Assembly above mentioned. This contract was to continue for two years, for which time the State appropriation was available. The Act of Assembly also contemplated co-operative geologic work, and the contract above mentioned provided for such co-operative geologic work. The results of the work done under this agreement for the two years ending June 30, 1901, will be found in the report of the Commissioners to the Governor covering the work of those years. The Legislatures of 1901 and 1903 made appropriations for the work, and it was continued under the provisions of the original contract, a short contract, continuing the terms of the original agreement, being entered into. During the four years, for which appropriations were made by the acts passed at these sessions, no report was made of the progress of the work, and much of the data and results of these years work has not been readily available. A portion of the information has appeared in publications of the United States Geological Survey, but scattered through a number of volumes. A full list of the completed topographic maps, and of the completed geological folios and other publications, now published, and a statement of the state of advancement of those in progress, will be found in the appendices of this report, and in the index map accompanying this report. Under the terms of the contract the expenses of the field work of all kinds, and of the office work in the preparation of the manuscript maps and reports of the geological work, is borne jointly by the United States Geological Survey and the State of Pennsylvania, but all additional work and expense incident to the printing of the maps and reports is borne by the United States Geological Survey alone. The topographic maps are printed in three colors, which means the engraving of that number of copper plates for each map. In addition, the geological folios have each several additional maps, and each of these require additional engraved plates, the number depending upon the features depicted on each map. There is no better work done than on these maps, and it is certainly advantageous to the State of Pennsylvania that this work is done without expense. The laws of the United States require that these maps and folios shall be sold at cost. The maps are sold at a uniform rate of 5 cents per standard sheet, and the folios at the rate of 25 cents per standard folio, with a liberal discount when ordered in quantities, so that the cost is not burdensome to those who may need them. (Directions for procuring them will be found elsewhere). The contract with the United States Geological Survey also provides that this Commission shall be furnished with transfers from the copper plates at cost of printing, so, when the State undertakes detailed geological work, all these maps are available for use, without the great expense of engraving. HISTORICAL. Prior to the appointment of the present Commissioners, in 1905, there had been appropriated by the Legislature the sum of $120,000 for co-operative work under the direction of the State Commissioners, and the United States Geological Survey had allotted a like sum, so that the work done prior to June 30, 1905, has resulted from a total expenditure of $240,000. Of this sum $196,000 was expended for topographic mapping and $44,000 for geological work. When the topographic work was first started there were but few accurately located points which could be used in such work. These had been determined by the work of the United States Coast and Geodetic Survey and the Lake Survey. The foundation of all mapping is the accurate location of a number of places, within the region mapped upon the face of the earth, and necessarily the first topo graphic work was confined to the regions adjacent to these determined points. (An outline of the methods used in locating such points will be found elsewhere in this report, under the head of "Methods of Topographic Surveying.") The co-operative work ending June 30, 1903, resulted in the mapping of portions of thirty-nine counties as follows: Erie, Center, Crawford, Jefferson, Butler, Armstrong, Indiana, Westmoreland, Allegheny, Washington, Greene, Fayette, Bedford, Fulton, Franklin, Lebanon, Berks, Juniata, Montgomery, Lehigh, Northampton, Tioga, Perry, Potter, Beaver, Blair, Dauphin, Huntingdon, Cumberland, Chester, Delaware, Lawrence, Clearfield, Cambria, Somerset, Snyder, Lancaster, York and Adams. The results of the co-operative topographic work, published prior to January 1, 1905, are to be found in 53 atlas sheets, and the field work was completed on nine others, and partly completed on six additional quadrangles. Pennsylvania has an area of 45,215 square miles, and the topographic map when completed will be published in 223 atlas sheets, each covering the area embraced in a quadrangle one-fourth of a degree on each side. Including 7,249 square miles mapped by the United States Geological Survey prior to co-operation, (in the anthracite coal region), 16,959 square miles had been mapped by January 1, 1905. The co-operative geologic work from 1899 to 1905 covered portions of twenty counties, as follows: Fayette, Greene, Washington, Westmoreland, Butler, Armstrong, Indiana, Allegheny, Beaver, Berks, Carbon, Lehigh, Northampton, Tioga, Potter, Clearfield, Center, Cambria, Blair and Bedford, covering about 5,000 square mlies. The publication, (at the expense of the United States Geological Survey), of geological results is necessarily much slower than of the topographic work, as it involves the drawing of geological maps, the preparation of sections and cuts, and of text, and necessarily involves the engraving of a larger number of plates and extreme care in printing. Such, in brief, were the results of the co-operative work, June 30, 1905, and your present Commissioners cannot but feel the State of Pennsylvania is to be congratulated upon the results of the work. WORK OF 1905-1906. At the time of the organization of this Commission, June 13, 1905, co-operative topographic work was in progress on six quadrangles, as follows: Honeybrook (Suplee), New Cumberland, Millerstown, |