498 WRITINGS OF JOSEPH HENRY. [1875 



Established Superiority of Lard Oil. — In regard to the com- 

 parative character of lard and colza oils we may be allowed 

 to print the following letter from Colonel Hamilton, the 

 manufacturer of the latter oil, who was present at the trial 

 to which he alludes: 



Fond du Lac, Wis., May 16, 1868. 



Dear Commodore : I must confess my great disappointment at the result 

 of the experiments at Staten Island. It is however not really so much the 

 failure of rape-seed oil as the undeniable excellence of lard oil as a burner. 

 I fully believe that our rape-seed oil of this year is as good as any that was 

 ever made in Europe, and I know it is far better than any we have ever 

 before made. I am satisfied now that for self-heating lamps there is no oil 

 that will bear comparison with lard, but I am equally satisfied that no colza 

 oil will yield a better result than ours under exactly the same tests. We 

 have but one more experiment to make with colza ; it is its extraction by 

 chemical displacement. If this fails we shall abandon the whole business. 



If all things are put together, I think the following statement will be 

 allowed, to wit: Our colza oil is equal to any foreign colza. It is better 

 than any we have heretofore made. It is better than sperm oil or any other 

 burner, excepting only lard oil. Our failure then is owing to the superior 

 excellence of lard oil, which, under the persistent investigation of the board, 

 has been shown to be the best and cheapest safe illuminator available. 



The board are entitled to great credit in producing this result. It will be 

 remembered that but a few years since, lard oil was pronounced unsuitable 

 for light-house purposes, but the perseverance of the board has brought 

 out the fact that it is much the best and cheapest oil, and that the expenses 

 of lighting the coast and harbors have been thereby greatly reduced. Surely 

 the country at large should acknowledge this, and give due credit to the 

 board. We have endeavored to do with colza what the board has effected 

 with lard oil, and we have been unsuccessful both for ourselves and the 

 light-house interest. The undertaking has been no source of profit to us, 

 and had the capital and time that have been devoted to colza been used in 

 our other branch of manufacture (linseed oil), it would at least have re-im- 

 bursed us with a fair remunerative return. As regards the oil we have 

 offered, we have hoped the board would take it. I do not think we can im- 

 prove upon the quality, and it is the last we shall venture to offer to the ac- 

 ceptance of the board, for we shall henceforth abandon the manufacture, 

 except for local wants. 



We are grateful to each member of the board for the interest they have 

 always shown in our undertaking, and for their uniform kindness and courtesy. 

 Accept, my dear Commodore, for yourself and your associates in the board, 

 my warmest thanks for your many kind expressions of interest, and believe 

 me, truly and gratefully, yours, 



C. S. Hamilton. 



Com. A. A. Harwood, U. S. N., 



Secretary Light-House Board, Washington, D. C. 



From the date of the introduction of lard oil in 1865, ^QQ, 

 and '67, until the end of 1873, when the attention of the 

 board was again directed to the stud}' of mineral oil, con- 

 tinual improvements were made in the processes of its pres- 

 ervation and inspection, and also in the lamps and other 

 appliances for its employment, and nothing further as a 



