88 FISH AND GAME. 



immediate vicinity where local titles are in vogue. To facilitate the identi- 

 fication of any body of water for public information or for stocking, the 

 primary essential is the recording of all the names by which the pond is 

 known. 



(2) Location. The situation of the pond as to the ease or difficulty of 

 access from railroad stations or nearest villages, as well as the hotel and 

 boating facilities, were recorded for use in future shipment of fry and 

 fingerlings, and as a source of information to fishermen. 



(3) Area. No actual survey of the area of the ponds was made, the 

 size being measured from maps or taken from old records. 



(4) Depth and Bottom. Soundings were so made that the contour 

 lines, giving the depths, could be charted on diagrams of the ponds, and 

 from these measurements the average and maximum depths were ascer- 

 tained. The sounding lead was equipped to take samples of the bottom 

 soil, but, unfortunately, on hard or mossy bottom no soil could be gathered 

 by this method, and the nature of the bottom could only be estimated in 

 shallow water from the character of the shores. 



(5) Water. The color of the water was listed either as clear, green or 

 brown. The turbidity was expressed in feet, the number representing the 

 distance below the surface at which a white four-inch circular disc would 

 disappear from view. By means of a maximum and minimum ther- 

 mometer the temperature at the bottom was taken in various parts of the 

 pond to determine the presence of springs. In the deepest part of the 

 pond a series of readings was taken at intervals from 1\ to 5 feet, to deter- 

 mine the thermocline (described by Dr. E. A. Birge of Wisconsin), or 

 point where the temperature drops rapidly. Deep ponds have three 

 layers of water, a surface layer, in which the temperature to a depth of 

 15 to 20 feet remains approximately the same as at the surface; a middle 

 layer or thermocline, in which there is a rapid fall; and a bottom layer, of 

 uniformly low temperature. The extent and nature of these three layers, 

 which vary in different ponds and at different seasons of the year, are of 

 importance as regards fish life from the standpoint of food and oxygen. 



(6) Shores. The shores around the pond were classified as woodland, 

 the kinds of trees being noted, and fields whether cultivated or unculti- 

 vated, such as pasture, meadow and marsh land. The height and slope 

 of the shores and character of the beaches were likewise noted. Cottages, 

 hotels, gunning stands, icehouses, etc., were recorded as indicating the 

 popularity of the pond as a pleasure resort. 



(7) Inlets and Outlets. The inlets and outlets, with the volume of 

 water, temperature, amount of sediment and pollution, such as manu- 

 facturing waste or sewage, were described. The presence of a dam at 

 the outlet indicated that the pond either had been raised above its original 

 area or that it was wholly artificial. In certain instances it was prac- 

 tically impossible to determine definitely whether a pond thus raised was 

 originally a State pond. 



(8) Fish. Information concerning the different species of fish was 



