AMERICAN INSTITUTE. • 87 



Among the chapters of that work, is one devoted to light- 

 houses and their improvement, and containing the general prin- 

 ciples and many details of a most admirable system for distin- 

 guishing lights, by causing them to show their numbers by rapid 

 eclipses and flashes of light. Any digit may be expressed by an 

 equivalent number of occultations and restorations of the light ; 

 thus, one eclipse and one restoration would stand for the number 

 one. The value of the digit, whether belonging to the units, 

 tens, or hundi-eds' place, might be indicated by occultations pre- 

 ceded by shorter or longer intervals of light, as three occultations 

 at intervals of a second would express three units, then a pause 

 of several, say three seconds, then five occultations would express 

 five in the tens' place, then a pause of three seeonds, and two occulta- 

 tions would express the hundreds, then a longer pause of say ten 

 seconds, would show that the number was complete. Thus, the num- 

 ber of a light-house might be repeated more than once in a minute, 

 even where the figures are quite high, and each light-house would 

 continue the repetition of its own number. Such lights can be seen 

 at least as far as others which are not temporarily obscured j and 

 by arranging the numbers of the light-houses along a coast, upon 

 such a system that the adjacent lights shall have very different 

 numbers, the figures representing units, tens, and hundreds of the 

 number not recurring in the adjacent lights, the distinctions can 

 practically be made very complete. For the world-wide purpose 

 of its inventor, but three digits are required. 



The mariner who approaches Sandy Hook, for example, would 

 see constantly repeated number me^ a flash for a second, darkness 

 for three. Let his pulse beat ever so irregularly from. toil and 

 anxiety, he could discern by it infallibly, that the dark interval 

 was three, the light one — and thus that this was the cynosure to 

 lead him to the haven where he would be. Nor could he mistake 

 Fire island light for Sandy Hook — for it would signal twenty-two, 

 first two, next two — but never one. 



Honor to the genius of this great inventor and philanthropist ! 

 How happy would we have been to welcome him amongst us, to 

 put the seal of his fame upon the details of the light-house sys- 

 tem. We envy not to Europe the possession of such ability, but 

 rather would seek to give it world-wide usefulness. Nor is this 



