168 FLORIDA GEOLOGICAL SURVEY-I3TH ANNUAL REPORT

vorite trip for sight-seers for many years. The spring is also used for bathing. Blue Spring in the same county near Juliette has nearly as large a flow, but does not make a navigable stream. Other well known springs in the same region are Weekiwachee Spring in. Hernando County and Sulphur Spring near Tampa. The former is rather unique in being in the midst of a large area of scrub.
 In the Gulf hammock region there are large springs at the head of the W"accasassa, Crystal, Homosassa (fig. 7) and Chessahowitzka Rivers. In the lake region the best known springs are DeLeon and Blue Springs in Volusia County, Palm and Hoosier Springs in the western part of Seminole County, Clay or Wekiva Spring, the main source of the \Vekiva River, Seminole Spring, near Sorrento, and Bugg Spring, near Okahumpka. Rock Spring, in the north-. wNestern part of Orange County (fig. 18), differs from most other Florida springs, and resembles some in the Appalachian Valley, in that the water rushes out audibly from the base of a cliff, instead of welling up from the bottom of a basin.
 The water of all these large springs. is highly charged with calcium carbonate, and is very clear, with a slight bluish tinge. Its temperature usually ranges between 700 and 750 the year round.* Some have a very perceptible sulphurous odor too, particularly those in Seminole County. Orange, Silver, Palm, Clay and Sulphui Springs and perhaps others are used more or less for bathing pools. Silver Spring, the largest and most accessible of all, is provided with glass-bottomed boats, from which the bottom can be viewed.
 The water of Green or Espiritu Santo Spring in Pinellas County and one or two smaller ones is believed to have medicinal virtues. There are a few salt springs near the St. John's River and some ot its tributaries, but little is known about them.
 Streams. The streams of, central Florida may be divided, chiefly on a basis of size, into branches, creeks, runs and rivers. The branches, generally speaking, are those small enough to stop running in dry weather, and they are not as numerous as in the northern part of the State, where the. effects of erosion are more evident. They are mostly clear or slightly cof fee-colored. The creeks flow throughout the year, and vary from a few feet to several yards

 *The temperature of a large spring in any part of the world, unless it is a thermal spring, is usually very close to the average annual temperature of the locality, so that it seems warmi in winter and cold in summer, by contrast.