Science Sittings

New Zealand Tablet, Volume 07, Issue 45, 7 November 1907, Page 35

Science Sittings

By 'Volt'

The Rice Paper Tree

The rice paper tree, one of the most interesting of the flora of China, has recently been successfully experimented- with, in Florida, where it now flourishes with other sub-tropical and Oriental species of trees and shrubs. When first transplanted in American soil the experimenters expressed doubts of its hardness, fearing that it would, be unable to stand the winters. All these fears have vanished, however, and it is now the universal opinion that it is as well adapted to the climate of that country, as to that of the famed Flowery . Kingdom. It is a small tree, growing to a height of less than fifteen feet, and with a trunk or stem from three to five inches in diameter. Its canes, which vary in color according to season, are large, soft and downy, the form somewhat resembling, that noticed in those of the castor bean plant. The celebrated rice paper, the product of this queer tree, is formed of thin slices of the pith, which Is taken from the body of the tree in beautiful cylinders several inches, in length. The Chinese workmen apply the blade of a sharp straight knife to these cylinders, and, .turning them round, either by rude machinery or by hand, dexterously pare the pith from the circumference to centre. This operation makes a roll of extra (quality paper, the scroll being of equal thickness throughout*. After a cylinder has thus been pared, it is unrolled and weights are placed upon it, until the surface is rendered smooth "throughout its entire length. It is altogether probable that ii rice paper making, becomes an industry in the United States,' those primitive modes will all be done away with.

The TWes of the Ocean

'Of all the operations of nature in the whole world (says an exchange), there are none more regular in their courses than the tides of the ocean. So perfect is their action and so constant are they in their ebb and flow that the big maritime governments are able to figure out the height of each and every tide for every day and night more than a year in advance for any part of the earth's surface.

In most places the tides run about four to the twenty-four hours, two being flood, when the water sweeps in from the sea, and makes what is known as high water, and twc being ebb, when it sweeps back to the ocean, leaving low water.

Each of these tides lasts about six hours— that is, for five hours or more, the waters are on the move, rushing in or out, and they cease for a time, standing quite still in some places. Sometimes a tide will run flood on the surface while it is running ebb, below near the bottom. Places where this happens, are always likely to make danger spots for the mariner.

In the majority of places the tides rise and fall only a few feet, but on shores where the banks are very steep, falling off abruptly into deep water, it often happens that the tide, when it rises, comes in so fast that it pours through all narrow openings in cascadelike torrents, making, such things as v the famous ' bores ' which may be seen in places like the Bay of Fundy. In other places, again, there will be more or less than four tides in the twenty-four hours. Furthermore there are localities where hardly any tidal action at all can be observed. All these peculiarities have been studied, and are taken into account nowdays by the observers, who make up the tidal tables.

The First Iron Bridge

The first irou bridge ever erected in the world, and which is in constant use at the present time, spans a little river in the country of Salop, on the railroad leadIng frorm Shrewsbury to Worcester, England. It was built in the year 1778, and is exactly 90 feet in length. The total amount 'of iron used in the construction, was 378 tons. Stephenson, the great engineer, in writing concerning it, said, • When we consider the fact that the casting of iron was at that time in its infancy, we are convinced that unblushing audacity alone, could conceive and carry into execution, such an undertaking.

The largest structured the earth when compared with the size of the builders is the sail hill of Africa. Some of these mounds have been observed 15ft high and 9ft in diameter. If a human habitation were constructed on the same scale- it would be more than seven miles high.