DISCOURSE OF W. B. TAYLOR: NOTES. 423 



of the same wick into the two liquids and noting the height to 

 which each ascended in a given time, that the surface attraction of 

 the sperm was greater than that of the lard, or in other words that 

 the ascensional power of sperm was much greater than that of lard at 

 ordinary temperatures. This method was also employed in obtain- 

 ing the relative surface attraction of various other liquids; we say 

 surface attraction instead of capillarity, because it was found in the 

 course of these investigations that substances which had less capil- 

 larity (that is less elevating power in a fine tube) had greater power 

 in ascending in the meshes of a wick. The relative fluidity of the 

 different oils was obtained by filling in succession a pear-shaped 

 vessel with a narrow neck, of about the capacity of a pint, having 

 a hole in the lowest part of the bottom, of about a tenth of an inch 

 in diameter. Such a vessel filled with any number of perfect 

 liquids, would be emptied in the same time whatever their specific 

 gravity. As at any given horizon, inertia is directly proportional 

 to gravity, the heavier the liquid the greater would be the power 

 required to move it ; but the motive power would be in proportion 

 to the pressure, or in other Avords to the weight, and therefore all 

 perfect liquids should issue from the same orifice with the same 

 velocity. To test this proposition, eight fluid ounces of clean mer- 

 cury and then the same bulk of distilled water, were allowed to run 

 out of the vessel above mentioned : the time observed was the same 

 within the nearest second. It was found in repeating this experi- 

 ment with sperm and lard oils that the rapidity of the flow of the 

 former exceeded considerably that of the latter; the ratio of time 

 being 100 to 167. 



"The results thus far in these investigations were apparently 

 against the use of lard oil : it was observed however that in the 

 experiments on the flow of the two oils, a variation in the time 

 occurred, which could only be attributed to a variation in the tem- 

 perature at which the experiments were made. In relation to this 

 point, the effect of an increase of the temperature above that of the 

 atmosphere, on the flowing of the two oils was observed. By this 

 means the important fact was elicited that as the temperature was 

 increased, the liquidity of the lard increased in a more rapid degree 

 than that of the sperm, and that at the temperature of about 250 F. 

 the liquidity of the former exceeded that of the latter. A similar 

 series of experiments was made in regard to the rapidity of ascent 

 of the oil in the wick, and with a similar result. At about the 

 temperature of that before mentioned, the ascensional power of the 

 lard was greater than that of the sperm. These results were recog- 

 nized as having an important bearing on the question of the appli- 

 cation of lard oil as a light-house illuminant. It only required to 



