Letter from Stephen Pleasonton to the Honorable John P. Kennedy, Chairman, Committee on Commerce, U.s. House of Representatives, regarding the progress of the installation of the first Fresnel lens in the United States at Navesink Twin Lights, December 28, 1841


Treasury Department,
Fifth Auditor's Office, December 28, 1841

Sir: In my letter to the Committee on Commerce of the 14th of December, 1840, they were informed that a workman had been sent from France, at the request of this office, by Mr. Lepaute, the manufacturer of the lenticular apparatus, for the purpose of fitting up in the best manner two sets of the lenticular apparatus in our two light-houses at Navesink, near Sandy Hook, and that it was expected the work would be completed before the close of the last year. In consequence of the inclemency of the weather, however, this work was not completed and both lights in operation before the month of March of the present year.

While the light of one tower was extinguished, and the work of putting up the lenses was in progress, a temporary light was erected and used of the same character; and while the work on the second tower was in progress, the character of the temporary light was changed to suit the occasion, (the one being a stationary and the other a revolving light;) so that the character and appearance of the original lights were preserved, and vessels coming in from sea could readily recognize them, until both sets of lenses were fitted up and put in operation. The temporary light is still preserved , with all its apparatus, to be used in case of any accident happening to either of the lens lights.

This being our first attempts to use the lenticular apparatus, the expense attending it has been greater than it would be in a similar case hereafter. The expense of a workman from France, who, coming to this country late in the season, was obliged to prosecute his work in the short days of winter, many of which were too inclement for him and those associated with him to work, the cost of a lantern made under his direction amounting to nearly thrice as much as one can now be made for, and many other expenses incurred at his suggestion can be avoided in future, if it be thought proper by Congress to authorize any more of the lenses.

Upon a rough estimate of the cost of these two sets of lenticular apparatus, of the first and second order, and putting them up upon two light-houses already built, it appears to be between $23,000 and $24,000.

The cost of these lenses, however, is nothing compared to the beauty and excellence of the light they afford. They appear to be the prefection of apparatus for light-house purposes, having in view only the superiority of the light, which is reported by the pilots to be seen in clear weather a distance of forty miles. It was my intention to have had the distance accurately ascertained by means of one of the revenue cutters, but I have not yet had an opportunity to do so. There are some drawbacks, however, in relation to their management, which would render them unfit for use in the United States upon a large scale, there being but one lamp which supplies all the light, with three or four concentric wicks, and this lamp, made upon the carcel principal, is very apt to get out of order, and the light become extinguished, if the keeper be not an intelligent mechanic, and capable at all times of making the necessary repairs.

We have been fortunate as to obtain such a keeper at Navesink, a man who can make every part of the machinery, both of the lamp and the clock-work, and apply it in case of necessity without the least delay, and he is a man, moreover, who appears to take a pride in doing his duty in the best and most satisfactory manner. He has attached to him three assistants, taken from the class of seafaring men, who watch alternately every two hours through each night, and being near the city of New York, with which he can communicate in a few hours, he can always obtain men of a suitable character as assistants, and also all necessary materials for making every part of the machinery and keeping it in use.

There is not a single keeper, out of about two hundred and forty, in charge of the reflector lights, so far as my knowledge extends, who is capable of taking charge of and conducting a lens light properly; and there are few in our country who are capable and would be willing to receive the inconsiderable sum for their services which we give Mr. Lopez, the present keeper at the Navesink, viz: $600 for both lighthouses. It would, therefore, only be in the vicinity of large towns that we should have it in our power to obtain suitable keepers, and at the same time proper assistants, and materials with which to repair the machinery, and of course it could only be in the vicinity of those towns that it would be advisable to employ the lenticular apparatus.

The consumption of oil in the two lenticular light-houses has been upon an average three gallons a night, whilst the consumption of thirty-one Argand lamps, previously used, was about the same quantity, being thirty-two gallons per lamp. The light from these lenses, however, is unquestionably better, but in what precise degree has not been ascertained. [the letter continues at this point speaking about desiring to implement these lens in other facilities and other matters such as oil consumption, but nothing more about the lights at Navesink].

I have the honor to be, very respectfully, sir, your obedient servant,
S. Pleasonton.

Hon. John P. Kennedy,
Chairman, Committee on Commerce, Ho. of Reps.

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