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!
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"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.
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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_.
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