COMBINATIONS OF THE KALEIDOSCOPE.
The system of endless changes is one of the most astonishing properties of the Kaleidoscope. With a number of loose objects—pieces of glass, for example,—it is possible to reproduce any figure we have admired, when it is once lost. Centuries may elapse before the same combination returns; if the objects, however, are placed in the cell so as to have very little motion, the same figure may be recalled, and if actually fixed, the same pattern will return in every evolution of the object-plate. A calculation of the number of forms is given upon the ordinary principles of combination; namely, that twenty-four pieces of glass may be combined 13,917,242,888,872,552,999,425,128,493,402,200 times—an operation the performance of which would take hundreds of thousands of millions of years, even upon the supposition that twenty combinations were effected every minute!
"THE MEANS TO THE END."
From the abundance of clay upon its site, London is, as might be expected, a brick-built city; although the ingenuity of our age has cased miles of streets with cement, to imitate stone. This prevalence of clay is, in great measure, explanatory of the vastness of the metropolis. It is nowhere better illustrated than in the fact of "the Five Fields," (between Pimlico and Chelsea,) formerly a clayey swamp, being now the site of some of the finest mansions in London. A few years ago, the clay retained so much water that no one would build there, and "the Fields" were the terror of foot-passengers proceeding from Westminster to Chelsea after nightfall. At length, Mr. Cubitt, on examining the strata, found them to consist of clay and gravel, of inconsiderable depth. The clay he removed, and burned into bricks; and by building upon the substratum of gravel, he converted this spot from the most unhealthy to one of the most healthy, to the immense advantage of the ground landlord and the whole metropolis. This is one of the most perfect adaptations of the means to the end, to be found in the records of the building art.
INDIA RUBBER, A CENTURY AND A HALF
SINCE.
Every generation is wisest in its own conceit, and the present is continually overrated at the expense of the past. Who would have thought that India rubber cloaks were worn in South America upwards of a century since? yet such, forsooth, is the plain fact of history; and disinclined as we are to rob Mr. Macintosh of the merit of his adaptation, the invention must be awarded to another age; indeed, it is almost one of the antiquities of the New World. In a work entitled La Monarchia Indiana, printed at Madrid in 1723, we find a chapter devoted to "Very profitable trees in New Spain, from which there distil various liquors and resins." Among them is described a tree called ulquahuill, which the natives cut with a hatchet, to obtain the white, thick, and adhesive milk. This when coagulated, they made into balls, called ulli, which rebounded very high, when struck to the ground, and were used in various games. It was also made into shoes and sandals. The author continues:—"Our people (the Spaniards) make use of their ulli to varnish their cloaks, made of hempen cloth, for wet weather, which are good to resist water, but not against the sun, by whose heat and rays the ulli is dissolved."
India rubber is not known in Mexico at the present day by any other name than that of ulli. And the oiled silk covering of hats very generally worn throughout the country by travellers is always called ulli.