6 GEORGE V SESSIONAL PAPER No 38a A. 1916 



XV. 



HYDROGRAPHIC INVESTIGATIONS IN THE ST. CROIX RIVER AND 



PASSAMAQUODDY BAY IN 1914. 



By E, Horne Craigie, University of Toronto. 



(With One Chart and Twenty-three Figures.) 



During the month of August, 1914, the writer, under the direction of Dr. J. W. 

 Mavor, and with his constant and active assistance, undertook to make a series of 

 hydrographic observations in Passamaquoddy bay and the St. Croix river. The object 

 of this work was to obtain as much information as possible not only about the actual 

 temperatures and densities of the water, but also about the nature of the currents of 

 warm and cold water, how these are affected by the tides, etc. Such observations, 

 besides being of importance and interest in themselves, are valuable on account of 

 tbeir bearing upon the haunts and habits of fish frequenting the waters studied, or 

 passing through these waters in their migrations. 



It is to be regretted that, owing to lack of apparatus, the work could not be 

 started earlier in the season, and that, on account of the other work being carried 

 on at the same time, more data could not be obtained. It is also regrettable that no 

 current-meter of any kind was to be had, as some. observations with such an instru- 

 ment would undoubtedly throw much light upon the subject by indicating the direc- 

 tion and strength, as well as the fluctuations of the currents at various points. 



For taking the temperature observations, reversing thermometers were used. 

 These have already been described in the report on the hydrographic work in connec- 

 tion with the " Investigation of the Bays of the Southern Coast of New Brunswick 

 with a View to Their Use for Oyster Culture." The Pettersson-Nansen water-bottle, 

 with which the water samples were obtained at points of considerable depth, is 

 described in the same report. At points near the surface and at the shallower stations, 

 the water samples were taken by means of a small water-bottle manufactured by 

 Negretti and Zambra, London. This consists of a brass cylinder holding a little less 

 than a pint, into the top and bottom of which fit two caps connected by a rod. The 

 top of the rod is held by a hook above the cylinder, the bottle thus being kept open, 

 and in this condition it is lowered to the depth where a sample is to be taken. A 

 messenger is then sent down the line and releases the hook, whereupon the caps are 

 pulled into place by two springs inside the cylinder, thus closing the bottle firmly. 

 In order to be sure that the sample represented the water at the point where the bottle 

 was closed, the bottle was jerked up and down a little and allowed to remain a few 

 moments before the messenger was sent down. 



The Richter thermometer,^ which was attached to the Pettersson-Nansen water- 

 bottle, was always allowed to remain down five minutes, while the Negretti-Zambra 

 thermometer- was usually left for three minutes, these times having been found to 

 allow the thermometers to give accurate readings. It was found that the correction 

 for the expansion of the mercury column at the temperatures measured averaged 

 about twenty-five thousandths of a degree, which was neglected in recording the tem- 

 peratures. 



1 Laboratoire Hydrographique, Kobenhavn, Preisliste, 1914, No. 75, Thermometer No. 164. 

 2MaghnarLi pattern frame, Negretti and Zambra thermometer No. 170,664. 



