[69] U. S. FISH COMMISSION STEAMER ALBATROSS. 71 



It will be readily observed that it is a iiiodificatiou of the Sigsbee 

 water si)ecimeu cup. The latter is well adapted for its purpose of col- 

 lecting water specimens for specific gravities, but it will uot retain the 

 free gases in water intended for chemical analysis. Feeling the want 

 of a bottle that would accomplish this desired end, Drs. Kidder and 

 Flint devised one during the summer of 1884, which was made by D. 

 Ballauf, of Washington, D. C, and sent to the Albatross for trial, and, 

 after testing it, a few improvements suggested themselves to the writer 

 and are embodied in the bottle figured. 



We consider tliis bottle still in the experimental stage, although it has 

 been very carefully constructed and has successfully withstood a press- 

 ure of 150 pounds per square inch. It is a. well-known fact, however, 

 that mechanism does not work as well under Avater as in the atmos- 

 phere, yet we anticipate good results from the apparatus in its present 

 form. 



THE NEGEETTI & ZAMBKA DEEP-SEA THERMOMETER. 



The following description of this thermometer is copied, in part, from 

 the catalogue of Negretti & Zambra, various eliminations and additions 

 being made by the writer. 



The construction of this thermometer will be readily understood by 

 referring to Plate XXXVIII, Fig. 2, where it is shown in a vertical sec- 

 tional elevation of Tanner's improved deep-sea thermometer case. 



The thermometrical fluid is mercury; the bulb containing it is cylin- 

 drical, contracted in a peculiar manner at the neck a; and upon the 

 shape and fairness of this contraction the success of the instrument 

 njainly depends. Beyond a the tube is bent and a small catch reser- 

 voir at h is formed for a purpose to be presently explained. At the 

 end of the tube a small receptacle c is provided. When the bulb is 

 downward the glass contains sufficient mercury to fill the bulb, tube, 

 and a part of the receptacle c, leaving, if the temperature is high, suffi- 

 cient sjjace in c. When the thermometer is held bulb upward the mer- 

 cury breaks at «, but by its own weight flows down the tube filling c 

 and a portion of the tube above c, depending upon the existing tem- 

 perature. The scale is accordingly made to be read upward from c. 



To set the instrument for observation it is only necessary to place 

 it bulb downward, when the mercury takes the temperature just as in 

 an ordinary thermometer. If at any time or place the temperature is 

 required, all that has to be done is to turn the thermometer bulb up- 

 ward and keep it in this position until the reading is taken. This may 

 be done at any time afterward, for the quantity of mercury in the 

 lower part of the tube which gives the reading is too small to be sen- 

 sibly affected by a change of temperature, unless it is very great; 

 while that in the bulb will continue to contract with greater cold and 

 to expand with greater heat. In the latter case some mercury will ijass 

 the contraction a and may fall down and lodge at h, but it cannot go 



