492 SURVEYING sus The 36 sections of each township are numbered in order, beginning with the N. E. corner and thence proceeding along the N. side of the township to section 6 in the N. W. corner; section 7 begins the next line of sections 8., the numbers running E. to 12, and then begin- ning the third line with 13 and running W. to 18, and so on, bringing No. 36 in the S. E. corner of the township. The quarter sections are designated by their position as N. E., N. W., S. E., and S. W. Fractional sections of irregular shapes are admitted on the borders of lakes, rivers, &c. With these explanations any tract may be readily pointed out upon the government maps from its abbreviated descrip- tion, or any locality in the wildest territory may be correctly defined ; thus the S. W. qr. sect. 13, T. 66 N., R. 34 W., meridian Michi- gan, is traced directly to an old mining loca- tion near the N. E. extremity of Isle Royale, Lake Superior. The law which established this system, while it required that the N. and S. lines should be true meridians, also required that the townships should be six miles square. To satisfy both of these conditions is physi- cally impossible, for the figure of the earth causes the meridians to converge toward the pole, thus making the N. line of each town- ship shorter than its S. line; an inequality which becomes more and more marked the higher the latitude of the surveys. Provision is consequently made for correcting the errors thus caused, by establishing what are called correction lines, which are parallels bounding a line of townships on the north when lying N. of the principal base, or the S. line of townships when lying S. of the principal base, from which the surveys as they are continued are laid out anew, the range lines again start- ing at correct distances from the principal me- ridian. In Michigan these correction lines are repeated at the end of every tenth township, but in Oregon they have been repeated with every fifth township. The instructions to the surveyors have been that each range of town- ships should be made as much over 6 m. in width on each base and correction line as it will fall short of the same width where it closes on to the, next correction line N. ; and it is further provided that in all cases where the exterior lines of the townships shall exceed or shall not extend 6 m., the excess or deficiency shall be specially noted and added to or de- ducted from the western or northern sections or half sections in such township, according as the error may be in running the lines from E. to W. or from S. to N. In order to throw the excesses or deficiencies on the N. and on the W. sides of the township, it is necessary to survey the section lines from S. to N. on a true meridian, leaving the result in the N. line of the township to be governed by the onvexity of the earth and the convergency of the meridians. Navigable rivers, lakes, and islands are " meandered " or surveyed by the compass and chain along the banks. The in- struments employed on these surveys, besides the solar compass, are a surveying chain 33 ft. long of 50 links, and another of smaller wire as a standard to be used for correcting the former, as often at least as every other day ; also 11 tally pins made of steel, telescope, targets, tape measure, and tools for marking the lines upon trees or stones. In surveying through woods, trees intercepted by the line are marked with two chops or notches, one on each side ; these are called sight or line trees. Other trees near by not touched by the line are blazed on two sides, quartering toward the line ; but if at some distance from the line, the two blazes should be near together, on the side facing the line. These are generally found to be permanent marks, not only recognizable for many years, but carrying with them their own age by the rings of growth around the blaze, which may at any subsequent time be cut out and counted as years ; and the same are recognized in courts of law as evidence of the date of the survey. They cannot be ob- literated by cutting down the trees or other- wise without leaving evidence of the act. Corners are marked upon trees if found at the right spots, or else upon posts set in the ground, and sometimes a monument of stones is used for a township corner and a single stone for section corners; mounds of earth are made where there are no stones nor timber. At the corners the four adjacent sections are desig- nated by distinct marks cut into a tree, one in each section. These trees facing the corner are plainly marked with the letters B. T. (bearing tree) cut into the wood. Notches cut upon the corner posts or trees indicate the number of miles to the outlines of the town- ship, or, if on the boundaries of the township, to the township corners. A useful text book is the "Treatise on Land Surveying" of W. M. Gillespie (new ed., New York, 1875). SURVILLE, Marguerite Eleonore Clotilde dc Vallon- Chalys de, a French lady of the 15th century, the reputed authoress of remarkable posthu- mous poems first collected in 1803 by Vander- bourg. They have been ascribed to her de- scendant, the marquis Joseph Etienne de Sur- ville, a royalist executed in 1798, and with less probability to the publisher Vanderbourg him- self. The poems are in the style of the 15th century, and refer to Clotilde's husband Beren- ger de Surville, who fell during the defence of Orleans against the English. Other parts of them are believed to apply to the persecutions endured by Louis XVI. The publication has given rise to a long controversy, but even those who, like Villemain and Sainte-Beuve, ques- tion its genuineness, unite in praising the ge- nius of the work. SUS, a territory of Morocco, comprising the Atlantic coast of that country between the Atlas mountains and the river Asaka or Nun, and extending E. to the country called Draa ; area, about 11,500 sq. m. ; pop. estimated at 750,000. It is mostly mountainous, the climate
