The salinity and temperature of the Irish Channel and the waters south of Ireland / by Donald J. Matthews.

  • Matthews, Donald John, 1873-1956.
Date:
1914
Catalogue details

Licence: In copyright

Credit: The salinity and temperature of the Irish Channel and the waters south of Ireland / by Donald J. Matthews. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    THE SALINITY AND TEMPERATURE OF THE IRISH CHANNEL AND THE WATERS SOUTH Of iREl^ND. The investigations on which this report is founded were commenced in February. 1903, and include observations up to the end of May, 1912. They consist of determinations of tem- perature and salinity during the months of February, May, August and November made on board the Hclga*and of observa- tions made at all times of the year up to 1907 at three lightships and one lighthouse, and thereafter at one lightship. On the four quarterly cruises Ekman reversing waterbottles with messengers have been used, generally in series, for ob- servations below the surface and on occasion at the surface also. They are fitted to carry two thermometers of the revers- ing type but as a rule only one has been used. The thermo- meters were of the pattern made by Richter of Berlin, with which it is possible to read to the second place of de- cimals, but the temperatures cannot be considered accurate to this extent as differences as great as -05° have been found between simultaneous readings of two instruments after applying all corrections. The fact that the thermometers have not been used in pairs also throws a certain doubt on the results, as these instruments are liable to sudden changes in the breaking-off point of the mercury thread, which may give rise to errors of considerable magnitude. Large errors are, of course, easily detected by the irregularity in the resulting tem- perature curve, but small ones may be overlooked if a second thermometer is not used as a control. An examination of the observations makes it almost certain that no large errors have occurred, but the small differences mentioned above are probably duet to such changes. During the earlier years of the investigations maximum- minimum thermometers were chiefly used and also reversing thermometers of Negretti and Zambra’s older model. The latter were graduated to half degrees and were unprovided with auxiliary thermometers, and temperatures could only be recorded to the nearest tenth of a degree. As regards the maximum-minimum thermometers, since in the areas in which Donald J. Matthe Plates I-XV. BY Apparatus. Fisheries, Ireland, Sci. Invest., 1913, IV. [1914].