Can any of your readers inform me if there is such a thing as a good and honestly constructed cyclopædia--one that does not send you hunting for information from one volume to another, and refer you backwards and forwards to articles that do not exist?

     I have been repeatedly annoyed by this kind of will-o'-the-wisp, but have to-day met with such an outrageous example of it, that, although it involves some trouble, I feel it to be a duty to make a public exposure of it in your columns.

     Requiring some facts on unusual atmospheric refraction, I turned to "Refraction" in the "English Encyclopædia." This article referred me to "Mirage, Fata Morgana," &c., for information on this branch of the subject. Turning to "Mirage," I found not a word, but another reference to "Reflection and Refraction, Atmospheric, Extraordinary." Next I tried "Fata Morgana," again the same reference. Coming back to letter R, I found the article "Reflection and Refraction," but was here referred to "Light, Optics, Refraction, Refrangibility;" then to letter A, "Atmosphere, Atmospheric"--nothing on the subject. Letter E, "Extraordinary Refraction"--nothing but a reference back again to "Mirage!" "Light, Optics, and Refrangibility" contain nothing on the subject.

     I was thus sent on a search through five volumes of the work, and made to hunt out nine distinct headings for what does not exist; and what makes the matter worse is, that the writer of the article "Refraction," at the end of the work, must have known that it did not exist when he referred back to "Mirage, Fata Morgana," &c., which words have not a word of information appended to them.

     An alphabetical cyclopædia is so much the most convenient for reference, and might be such an invaluable addition to a library, that it is the more to be regretted that it should be brought into disrepute by the absence of all efficient editorial supervision.