62 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT. 



only one sample from each swamp or bog was taken, on account of the 

 limited time available. For the same reason nearly half the samples were 

 dug out by hand from a depth of about a foot. The deeper ones were taken 

 with a sampling instrument devised by Dr. Chas. A. Davis, consisting of a 

 number of sections of half-inch iron pipe which could be screwed together, 

 one of them with a short transverse handle at one end, and a brass cylinder 

 nearly an inch in diameter and about nine inches long, which could be screwed 

 to the pipes and pushed down to any desired depth, and then filled with 

 peat from that depth by an ingenious mechanism. This cyhnder had to 

 be filled a good many times to obtain a sufficient quantity of peat for analysis, 

 and in practice each sample was made up from several taken from the same 

 depth within a few feet of each other. 



The next column after the name of the locality gives the depth from 

 which the sample was taken, and the last column on the first page the max- 

 imum depth of peat found in each deposit. In a few cases where this depth 

 was given me by other persons the figures are put in parentheses. 



The moisture percentage is taken from air-dry samples, and the other 

 determinations were made after the water was eliminated by heating slightly 

 above the boiling point (not enough to decompose or volatilize the peat.). 

 The ash was not analyzed, but it is probably chiefly silica in most cases, 

 though in the samples from Panasoffkee, Helena Run, and the south end 

 of the Everglades it must be mostly lime. The reason for determining the 

 sulphur (which is done more generally for coal than for peat) is that an 

 excess of it would have a corrosive effect on the iron parts of fire-boxes, 

 and might also be olpjectionable if the peat was made into illuminating gas. 

 The percentage of nitrogen gives some indication of the value of the peat 

 for agricultural purposes. 



The ash, fixed carbon and volatile matter (other than water) together 

 add up to ioo% in each case. The sulphur and nitrogen are part of the 

 volatile matter determined separately. The percentages of ash and fixed car- 

 bon added together give the amount of coke which may be obtained from 

 each sample, for in the process of coking enough heat is used to drive ofif 

 all the other ingredients. 



The fuel value is given in "British thermal units" per pound. A British 

 thermal unit is the quantity of heat required to raise the temperature of a 

 pound of water one degree Fahrenheit, or, to be more precise, from 50° to 

 51° F. If the fuel value is given as 10,000 B. T. U., for instance, this means 

 that a pound of the material if burned under the most favorable conditions 

 could be made to raise the temperature of 5 tons of water 1°, or i ton 5°, 

 etc. 



