46 U. S. COAST AND GEODETIC SURVEY 



131. With the older type gage, a thorough cleaning of the pencil 

 screw cannot be accomplished without disconnecting the wiring, and 

 this is generally undesirable. However, at regular intervals the 

 screw must be wiped clean with a rag moistened with kerosene or 

 nonleaded gasoline, and the best time to do this is when changing 

 the paper after the close of each month. With care to avoid letting 

 the float wire spring off of the drum, the screw may be turned a 

 limited amount to move the pencil arm forward and backward dur- 

 ing the cleaning process. A liberal application of kerosene or non- 

 leaded gasoline with a squirt can will be helpful in removing dirt 

 accumulated inside the pencil arm bearing. 



132. Clearing float well intake. — Particular care must be taken to 

 keep open the intake to the float well, as even a partial clogging may 

 destroy the value of the record by creating a lag in both time and 

 height of the tide. Clogging may be caused by an accumulation of 

 sediment inside the well, by marine growth at the intake, or by the 

 shoaling of the water in the vicinity. In an iron float well clogging 

 may result from an accumulation of iron rust scales inside the pipe. 

 A clogging of the intake is indicated by a smooth tide curve when 

 the water outside the float well is somewhat rough. Although the 

 float well is designed to dampen down the outside waves, there should 

 always be an unmistakable oscillation of the recording pencil when- 

 ever the water is somewhat rough in the vicinity. A smooth, regu- 

 larly traced curve is to be regarded with suspicion and should occur 

 only when the water outside the float well is smooth. 



133. In localities where there is any tendency toward clogging, the 

 observer should establish the practice of clearing the float well at 

 regular intervals. When clearing an iron float well with intake in 

 the center of the standard conical intake coupling, it will generally 

 be necessary first to remove the float from the well and, to avoid any 

 tangling of the float wire when raising the float, the wire should be 

 secured by a clamp or loop around some convenient object to take up 

 the slack. When the intake is not badly clogged it is most conven- 

 iently cleared by use of the cleaning tool shown in figure 16. This 

 tool is lowered into the well by a line and is used to tap out any 

 foreign matter which may have collected in the intake. 



134. If there is a considerable accumulation of sand in the bottom 

 of the well it may be necessary to use a jointed rod made up of sec- 

 tions of iron pipe which maybe fastened together as it is lowered into 

 the well. One-half-inch pipe with outside diameter a little less than 

 % inch will generally be found satisfactory for the purpose when the 

 diameter of the intake is an inch or more. If the obstruction in the 

 intake is found to be especially difficult to remove, a drill of suitable 

 size soldered in the end of the lowest section of pipe will usually be 

 found effective when other means have failed. 



135. For a wooden float well when the intake is in a lower corner 

 of a sloping bottom, the use of the jointed rod without removing the 

 float from the well will probably be found both convenient and 

 effective in ordinary cases. When the intake is in the side of the 

 well rather than the bottom, its clearing will generally be more diffi- 

 cult and necessitate the use of a boat at low tide. When the clogging 

 occurs as a result of the shoaling of the water around the float well, 

 the clearing of the intake becomes a problem which cannot be han- 



