.I60 FLORIDA GEOLOGICAL SURVEY-I3TH ANNUAL REPORT

 In recent years several test wells have been put down in the hope of striking oil-one in Sumter County reached a depth of 3,080 feet before it was abandoned-but without success as yet.*

 TOPOGRAPHY
 The subject of topography is not very well adapted to systematic or statistical treatment, especially in a region where so little is known of the processes that produced the configuration of the surface as is the case here. In most civilized countries the greater part of the topography is evidently the result of either glaciation or normal erosion or easily understood variations thereof, and persons skilled in such matters can trace the developmental cycles with considerable satisfaction; but surface erosion is probably an insignificant factor in our area, on account of the low altitude of some parts and the very sandy soil or subterranean drainage of other parts, and the origin of some of our topographic features is still an unsolved problem. The treatment adopted here, therefore, is necessarily somewhat empirical.
 Uplands. Although the topography of central Florida seems to have been shaped mostly by other means than surface erosion, as just stated, the steepest average slopes are generally in the most el*It is a curious coincidence, perhaps not easily explained, however, that all or nearly all the successful oil wells in the United States are in regions where there is more rain in early summer, (April to June) than in late summer (August to October), and where the native vegetation is either predominantly deciduous or treeless; a combination of conditions not found in Florida-though approached in the extreme northwest of the State-or anywhere near the c')ast northeast of here.
 According to an article by John K. Barnes in the "World's Work" for April, 1920, the cost of drilling for oil in the United States in recent years has greatly exceeded the value of the oil produced. So apparently we would be better off financially if no oil wells had ever been drilled!
 tAt first thought it might seem impossible to apply any sort of statistics to topography. But in areas covered by reasonably accurate topographic maps one could at least estimate the average slope of the surface of a given region by drawing straight lines across the map in various directions, counting the number of contours crossed in a unit distance, averaging the results, and applying a factor of about three-fourths to make a correction for the fact that mosi of the contours will not be intersected at right angles. It would also be possible to estimate the areas lying between sea-level and 50 feet, 5o and 100 feet. etc.