422 MEMORIAL OF JOSEPH JIENRY. 



seed was imported from France and distriljuted throujjh the agri- 

 cultural department of the Patent Office to different jiarts of the 

 country, with the hope tliat our farmers would be induced to attempt 

 its cultivation. .Vltliough the climate of the country a])peared 

 favorable to its growth, and special instructions were prepared and 

 distributed by the Light-House Board for its culture and the means 

 of ])roducing oil from it, yet the enterjirise Mas not undertaken with 

 any approximation to success, except in Wisconsin, where a manu- 

 factory of rape-seed oil was established by Colonel C. S. Hamilton, 

 formerly of the United States Army. To this manufactory the 

 Light-House Board gave special encouragement and ])urchased at 

 a liberal price all the oil that could be supplied. The quantity 

 however Avhich could be procured was but a small part of the illumi- 

 nating material required for the annual consumption of the Light- 

 House Establishment." 



After referring to some investigations made for the Board by 

 Professor J. H. Alexander, of Baltimore, the lieport quoted pro- 

 ceeds: "The chairman of the committee on experiments commenced 

 himself to investigate the qualities of different kinds of oil, and 

 wa<? soon led to direct his attention to the comparative value of 

 sperm and lard oils. The experiments made by Mr. Alexander 

 were with small lamps, and the comparison in this case (as will be 

 shown) Avas much against the lard oil. The first exj>eriment of the 

 new series, consisted in charging two small conical lamps of the 

 capacity of about a half ])int, one with pure sperm oil and the other 

 with lard oil. These lamps were of single-rope wicks each contain- 

 ing the same number of strands: they were lighted at the same 

 time, and the photometrical power ascertained by the method of 

 shadows. At fii'st the two were nearly equal in brilliancy, but after 

 burning about three liours, the flame of the lard had declined in 

 photometric power to about one-fifth of that of the flame of the 

 sperm. The question then occurred as to the cause of this decline, 

 and it was suggested that it might l)e due — first, to a greater specific 

 gravity in the lard oil, which would retard the ascent of it in the 

 wick after the level of the oil had been reduced by burning in the 

 lamp ; or second, to a want of a sufficient attraction between the 

 oil and the wick to furnish the recpiisite supply as the oil descended 

 in the lamp; or third, it might be due in ])art to the imperfect 

 liquidity of the oil, which would also militate against its use in 

 mechanical lamps. 



"The lard oil was subjected to experiments in regard to each of 

 these points. It was found l)y the usual method of weighing equal 

 quantities of the two fluids, that the specific gravity of the lard was 

 greater than that of the sperm; and also by dipping two portions 



