THE GROWTH OF STALAGMITES AND STALACTITES 123 



ACTUAL CLASSIFICATION OF STALAGMITES 



If a stalagmite is extremely unsymmetrical, it may be necessary 

 to classify it by sections. The classification, by circumference 

 alone (a more or less uncertain procedure), will indicate its period 

 of formation, but not how long ago it died. If a stalagmite is 

 young (immature) and its drip large, its circumference will be less 

 than that given in Table IV; if the stalagmite is young and its 

 drip small, its circumference will be greater than that given in the 

 Table IV. 



More than one drop per second is a fast drip, over 2 feet per 

 second (perceptible) is a large air circulation, over 50 per cent is a 

 high relative humidity, over 68° F. is a high temperature, and over 

 50 per cent is a high concentration. 



Count the drip, estimate the air, get the concentration by 

 analysis (the absence of a healthy stalactite above indicates a high 

 concentration if the cave has a pure limestone cover) , and determine 

 the temperature and humidity. If the stalagmite is in an open 

 cavern or shelter, the yearly average temperature and relative 

 humidity for the region may be taken. ^ A wet cave, of course, 

 means a high humidity. 



PRECAUTIONS NECESSARY 



After determining your limits, classify by the Dichoic Scale and 

 verify the measurements in Table IV. Always remember that the 

 classification involves the extreme limits of the variables, and if 

 unsatisfactory results are obtained re-examine the hmits and, if 

 any are doubtful, reclassify. Table IV is merely an approximation, 

 and the figures are given to several decimal places to prevent a 

 ragged appearance. 



EXAMPLES OF CLASSIFICATION RESULTS 



The actual figures are based on the Jockey Cap. Figure 16 

 shows an attempt to reconstruct this stalagmite from Dawkin's^ 

 measurements. On the basis of the foregoing calculations, this 

 stalagmite now (1922) has a circumference of 3.53 meters, or 139 

 inches, at the points located by Dawkins. 



^ " Climatological Data by Sections," U.S. Weather Bureau. 

 ^ Op. cil., pp. 40, 442, and Appendix II. 



