207 



Sounding Apparatus and Method of Using it. — A flat-bottomed boat 

 capable of running into shore at all points was manned by three persons. One 

 who was an expert and steady oarsman at the oars, one in the stern to take notes 

 and steer, and one in the bow to make the soundings. The sounding apparatus 

 consisted of a wheel two inches wide with a circumference at the bottom of a flat 

 marginal groove of one foot ten inches. (It had been ordered with a circumference 

 of two feet.) On the drum was wound 175 feet of fine annealed wire. This, when 

 wound, formed less than two layers over all parts of the drum. The weight con- 

 sisted of a round pebble as large as a fist and was tied in a piece of cheese cloth. 

 This was a very simple and efficient piece of apparatus. The weight, if lost, could 

 easily be replaced by one of several others carried along, and the wire was found 

 sufficient for the whole summer's work. The original cost plus the cost incident 

 to its operation did not exceed $1.50. The wheel was provided with a crank and 

 being of a definite circumference the depth was measured by the number of turns 

 it took to raise the weight from the bottom to the surface. This apparatus would 

 be efficient in any lake of moderate depth. To run a line of soundings the bear- 

 ing to the objective point on the distant shore were taken from the starting point 

 with a compass. The oarsman pulled thirty strokes, backed water and held the 

 boat. A sounding was made in the bow and the depth recorded by the man in 

 the stern. It was found that with the boat always used for the purpose, manned 

 as above in calm weather, when all the sounding was done, 30 strokes moved the 

 boat 300 feet. This method proved entirely satisfactory in short lines a mile and 

 a half in length. In long lines it proved unsatisfactory. 



Additions to the Equipment. A new laboratory 18x55 feet, two stories 

 high, will be ready for occupation by June 1 of 1896. 



A partial description of new apparatus devised for next summer's work may 

 be given. 



One flat-bottomed boat similar to sounding boat, 12 feet, 2 oars. 



One flat-bottomed boat 15 feet, four oars. Plankton apparatus. 



Three glass-bottomed galvanized iron boats about 12 inches in diameter to 

 explore bottom. 



One galvanized iron tube 2 inches by 20 feet, glass ends and funnels for fill- 

 ing or emptying, to determine color of water. 



Automatic recording apparatus to observe seiches. 



Plan op Wobk. — It must be understood that the undertaking was quite 

 expensive both in time and in money. The Indiana University endorsed the 

 plans and lent apparatus from the zoological laboratory with the provision that 



