APRIL, 1908. LAKES AMATITLAN AND ATITLAN MEEK. 167 



lake only a few feet from the shore, and then only at the surface. The 

 many bottom temperatures which I took in all parts of the lake did 

 not indicate any local sources of heat in the bed of the lake. I was 

 unable to secure a thermometer in the City of Guatemala which would 

 register over 110 F. and so I was unable to take the temperature of 

 the water as it came from these hot springs. The largest and hottest 

 one, near the station of Laguna, was hot enough to boil eggs very suc- 

 cessfully. In 6 minutes the egg would be soft boiled, at 10 to 12 

 minutes medium, and at 15 minutes the yolk would be hard but the 

 white was quite soft. 



The small fishes (Pcecilia sphenops} will swim nearly up to these 

 springs, but they remain in the cooler layer of water near the bottom. 

 They appear to be swimming in water hot enough to scald one's hand, 

 but in reality are in water not warmer than 90 or 100 F. A few of 

 these fishes were placed by me in water taken directly from the spring, 

 and these died almost immediately. These small fishes, although they 

 come very close to the spring, do so in the lower stratum of water. 

 The hot springs on the margin of Lake Amatitlan are too small and 

 too near the surface to have any influence on the general temperature 

 of the water in the lake. 



The water is only moderately clear. A white disc 12 inches in 

 diameter cannot be seen at a depth of over 10 to 15 feet, seldom over 

 12 feet. The same disc is plainly visible in Atitlan at a depth of 

 45 feet. The lack of clearness is due more to the abundance of Plankton 

 (microscopic animals and plants) in the water than to the fine, silt-like 

 material held in suspension. The water in Lake Amatitlan is slightly 

 alkaline, having a specific gravity of about 1.002 (specific gravity of 

 sea water is 1.027). Compared with water from Lake Michigan, it 

 contains relatively larger quantities of soda, potash, lime, magnesia, 

 soluble silica, and chlorine. It also contains a small quantity of iron 

 and aluminum. The following table gives a comparison of the more 

 common mineral substances as found in Lake Amatitlan and Lake 

 Michigan. The analysis of the water from Lake Michigan was made 

 in office of Chicago Board of Health; that of Lake Amatitlan by Mr. 

 R. Gwirz, in charge of the Government Chemical Laboratory of 



