SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XLIV, Issue 13497, 25 May 1907, Page 4 (Supplement)

SCIENCE, MECHANICAL INVENTIONS, ETC.

ALCOHOL FROM POTATOES. Germany leads to-day in the manufacture and use of alcohol for light and power. In that 'country potatoes are the chief source from which alcohol is produced. The potato crop last year reached the astounding proportions of 1,775,579,000 bushels, or more than 53,000,000 standard tons. Of this amount nearly one-half was used in the manufacture of alcohol and starch. Oneeighth of all the tillable land in Germany is planted in potatoes, which show an average production of 317 bushels an acre, which sold at an average of Is 2d a bushel, or about £12 an acre. In France alcohol for manufacturing purposes, is made chiefly from molasses and sugar beets.,

THE ; TUNGSTEN LAMP.

"It ie generally conceded that within a year an - electric glow lamp, the tungsten lamp, will be on the market," says Professor W. •S. Franklin, in Science, "and that the output of light per unit of power consumed will , be increased at least threefold above that which is now obtained by the carbon filament glow lamp." The writer adds that this means that the lightproducing capacity of every electric lighting station in, the world will be at once multiplied by three, with the possibility of greatly reduced prices per. unit of light, and also' greatly increased profits. * The tungsten lamp, in which a metallic filament takes the place -of • the ordinary/carbon loop, has received much attention in technical journals.

SCIENCE IN THE FUTURE.

;: Some years ago M. Berthelot, Sc.D., who recently died suddenly, made a remarkable speech at the banquet of the Syndical Chamber of Chemical Product Manufacturers, taking for his subject, " The World' in the Year 2000." Here is an extract — "When energy 'can be cheaply obtained food can be made from carbon taken from carbonic acid, hydrogen taken from water, and nitrogen taken from, the air. What work the vegetables have so far done science will soon be , able to do better, and with far greater profusion, and independently of seasons or evil microbes or insects. There will be then no passion to own land, * beasts . need not be bred for slaughter, man will be milder and more moral, and barren regions may be preferable to 'fertile as habitable-places, because they will not be pestiferous from ages of manuring. : The reign of chemistry will beautify the planet. • There will under it be no need to disfigure -. it with the geometrical works of the agriculturist, or with the grime of factories and chimneys. It will recover its verdure and flora." " The earth, in fact, M. Berthelot added, "will be a vast pleasure-garden, arid the human race will live ;; in peace and plenty." .

THE GREENWICH OBSERVATORY. Few people except sailors connect Greenwich Observatory with navigation, yet it was founded with the very practical object of making it possible ,to accurately determine the position of a ship at sea, says the Sydney Morning Herald. As late as the middle of the : eighteenth century navigation was in a most primitive condition, the only available method' of finding longitude being dead reckoning. The consequences were disastrous. On one occasion Commodore Anson, for instance, anxious to make the island of Juan Fernandez with a scurvy-smitten crew, : ran east, ; believing himself to be west of the island. He was, j however, really east of it, and made the mainland..of America.- Many of his crew died before he could turn • and reach the island. As soon, as the old' method of coasting gave way to a bolder system of navigation the want of means to determine the position of a ship was>keenly felt, -and it was one ;of the triumphs of * Galileo to suggest a method, which, however, though theoretically correct, proved impracticable. The problem, of finding longitude becomes the problem of finding the difference between the local time of the given place and the local time at a standard meridian. , The navigator obviously has no direct means of knowing what time it is, say,> at Greenwich,,but.,he can tell, this, by -observing the position of , the moon among the stars if he is provided, with a table of those positions for definite times drawn up in advance. In the Nautical Almanac the moon's distance J from certain stars is given for every three hours of Greenwich time, and it was to gather material'for a knowledge of the moon's motion ■ among the stars that. the j observatory was founded. The proposal was made by a Frenchman to Charles' 11. The project was favourably reported on by Flanisteed, who was \ accordingly, appointed the King's Astronomer, "to , apply : himself with the most exact care and. diligence to rectifying the tables of the motions of the heavens and the 'places: of the fixed stars;! in order to find out the so much desired longitude at sea for. the perfecting the art of navigation." This was in 1675. The astronomer's salary was £100, and he received full permission to supply himself with any instruments he might require at his own cost. The observatory was thus founded primarily for the benefit of the I navy and the mercantile marine; and this duty has been its fifst duty ever since. We do not generally hold up Charles 11. to admiration ; but he did some things towards laying; the s foundations of the Empire worthy of people with better reputations.

RISKS OF STEEL-CONCRETE CON-

STRUCTION.

A serious risk, which is none the less threatening because it is altogether unnecessary and preventable, exists in the new system of. concrete-steel construction which is .entering so ; largely into modern work, says the Scientific American, ' Its cheapness,: its !; apparent simplicity of design, the ease with which its materials may be ; assembled and the speed with which they ; can be thrown together into the finished work," have combined to render this new form of construction extremely popular. The peril lies in! the supposed . simplicity of the design and in the ease and speed with which " concrete-steel structures can be built". ,To these two causes chiefly, and generally to the latter, may be assigned the failures of concrete buildings, which .of late have become alarmingly frequent. Let it be understood then, in '■. the first place, that it?is not a simple matter, to properly design the posts, beams, girders, and floors of a concrete building; that is, to , design them so as to secure a maximum amount of strength with a minimum amount of maferial. It is hot nearly \so simple a matter as to design a building " composed of a structural steel, skeleton, with tile, concrete, or masonry floors and walls. Con-; crete-steel construction, in the present state of the art, is, scarcely out of its infancy. \ In spite of , the fact that it .has. been made the subjectj of much .laboratory and testing-J yard experiment, the sum total of clearly l ascertained and reliable data is not large. So true is this that there are few classes of work that come within the engineer's or architect's province, in which he is called upon to exercise such 'excellent judgment and to apply so carefully the facts and principles of his profession, as in concrete-steel construction. However, it is not here that the chief peril lies; not at least when, reputable engineers of standing in their profession are employed. It is when the plans are handed over to the builder with his gangs' of cheap labour that the trouble begins. . For unless the foreman or assistants, whose duty it is to watch the actual laying, and ramming of the concrete, are careful and intelligent in their oversight, it is possible for the work to be so carelessly; done as to greatly impair its strength, if i not to make certain-its ultimate collapse. : The; steel bars which reinforce what might Ibe called the lower chord of a concrete girder, or the exterior shell of a < column, ! : lose their value unless the concrete is everyi where so snugly rammed against them, i as to ; throw .them into intimate stress l relation ■'-; with the - girder or column as a i whole. : " Eternal vigilance" should be the watchword of the future;; if this new form of construction is to regain the reputation for combined cheapness" and. strength, which has been so severely imperiled by tM many .failures of the' past few months* ■■•;.■•.-.