TIDAL PHENOMENA OF THE ST. JOHN RIVER. 69 



feet four inches lower than Mr. Burpee's reference point. From 

 this I deduce that the south-west corner of the west pier of the 

 bridge is forty-one feet six inches above mean sea-level at St. 

 John; and that on August 9th the mean water level at Frederic- 

 ton was fourteen feet four inches above the mean sea level at 

 St. John. These figures maybe of some future use for reference; 

 and they are given for what they may be considered worth. 

 Exception may be taken to the use of railway levellings for such 

 a purpose, but other data are not to be had at present. I am 

 indebted to Dr. Harrison, of the University of New Brunswick, 

 for Mr. Burpee's figures. 



V. Tide Gauge Used. 



For the purjDose of the following work I used a self-recording 

 tide gauge of a simple type designed by myself and made with 

 the assistance of Mr. H. White of Fredericton. As a description 

 may 1)e of use to others I give the following brief account of it. 

 It consisted of a float to rise and fall with the water and a vertical 

 drum driven Ijy a clock, the parts being so arranged that a pencil 

 attached to the float traced a curve on a sheet of paper wrapped 

 around the rotating drum. The details and dimensions were as 

 follows : 



The float consisted of a cylindrical can plain at the top and 

 with a conical lower end, the lower end being loaded with shot 

 to give the float greater stability in the water. The diameter of 

 the can was five inches and its length without the conicrJ end 

 five inches, with the conical end seven and a half inches. 

 A brass tube was soldered axially through the can. Through 

 the tube a brass rod passed loosely so that the float might 

 slide up and down the rod as an axis. This axis was clamped 

 in the frame-work of the machine, so that it might be removed 

 and cleaned. Above the rod came the rotating drum, a 

 cylinder of wood twelve inches long and three inches in 

 diameter. The upper end of this made friction connection 

 with a spring clock by means of a small axial rod fastened to a 

 brass plate which was screwed to the wooden drum. The lower 



