The small reservoir, B, is indispensable to the well working of the apparatus; for in seeking the temperature at a certain depth the instrument may, on being drawn up, pass through warmer strata, and it is necessary, therefore, to provide the reservoir with a means of diffusing the small quantity of mercury resulting from this excess of temperature. The tube has also a small bulge at its upper extremity at C.
The thermometer is placed in a small wooden case having a double bottom throughout its length. In this double bottom are placed a certain number of lead balls that can run from one end of the case to the other, and of sufficient weight to render the instrument buoyant in sea water. To use the apparatus, one end of a cord is passed through a hole in the case under the reservoir of the thermometer, and the other end is tied to the sounding line at a certain distance from the lead ([Fig. 2]). While the line is descending the thermometer will remain reservoir downward ([Fig. 2]); but when it is again drawn up the thermometer case will take the position indicated in [Fig. 3], and the column of mercury breaking at A will fall into the capillary tube, the divisions of which, as will be seen at [Fig. 1], are reversed.
As to the thermometer itself, it is important to protect it against the pressure which becomes so considerable at great depths; to do this the reservoir is surrounded by an envelope of thick glass about three quarters full of mercury. The mercury serves to transmit the temperature to the reservoir, and should the exterior envelope yield to the effects of pressure, the reservoir proper would not be affected, the mercury not exactly filling the annular part which surrounds it.
[New Inventions.]
George E. Palmer, of Cedar Rapids, Iowa, has patented an improved Ironing Board, on which the garments may be held in stretched state while being smoothed with the irons, and readily adjusted thereon to any required degree of tension by a simple attachment.
William B. Rutherford and Joel T. Hawkins, of Rockdale, Texas, have patented an improved Bale Tie, which is formed of the plate provided with a longitudinal groove and cross ribs or loops, and having projections or keys to adapt it to receive and hold the notched ends of the bale band.
An improvement in Composition Pavements has been patented by John C. Russell, of Kensington, Eng. This invention relates to the treatment of peat and spent tan for the manufacture of an improved product or material suitable for paving roads and other places and for roofing, etc. The most important steps in making the composition consist in drying bruised or finely ground peat or spent tan, heating the same in vacuo to degree of 150° Fah., and adding sulphur and gas tar, gas pitch, and stearine pitch in the proportions specified, then kneading the mixture while heated and adding carbonate of lime and furnace slag.
Louis Blanck, of New York city, has patented an improved Safety Brake or attachment for locomotives and railroad cars, by which the entire train, either by a collision with another train or by contact with any obstruction, is first raised from the rails, and then moved in backward direction for the distance of a few feet, so that all danger of accident is avoided, and no other sensation than that of a slight rocking motion exerted. The attachment is constructed so as to admit of being worked by the engineer from the cab or the locomotive, or, if desired, from any car of the train.
An improved Evaporating Pan had been patented by Andrew D. Martin, of Abbeville, La. This invention consists in a tapering sheet metal tank having transverse partitions and longitudinal tapering flues that extend through all of the partitions and terminate at the ends of the tank.