MECHANICS AND USEFUL ARTS. 67 



rutes the basis and chief condition of progressed of every improvement- 

 A young man with a mind well stored with solid scientific acquirements, will, 

 without difficulty or effort, master the technical part of an industrial pursuit; 

 whereas, in general, an indivi lual who is thoroughly master of the technical 

 part may be altogether incapable of seizing upon any new fact that has not 

 previously presented itself to him, or of comprehending a scientific principle 

 and its application." LieUg, Letters on Modern Agriculture, edited by John 

 Blyth, M. D. 



NOVEL GEOGRAPHICAL EXPOSITION. 



A gentleman of Cumberland, England, has recently converted a level and 

 verdant plain on his estate into a map of the world, of great and singular 

 interest. It really gives learners an expertness in geography, much be- 

 yond what they acquire from books and maps. The spot is about 300 

 yards in length, from east to west, and 180 in breadth, from north to south. 

 It is inclosed by a wall of dwarf dimensions. Thirty-six marks are made on 

 it (east and west), and eighteen on the north and south, fixing the degrees 

 of longitude and latitude at ten degrees, or 600 miles asunder. Four pieces 

 of oak timber are laid down, 30 feet long and 8 inches square, with holes at 

 the distance of 3 inches, or five miles from one another, thus making 36 

 inches a degree, and comprising in ten a distance of 600 miles. The scales 

 afford an opportunity, by cross log lines, of determining particular towns 

 and cities, in the same manner as we operate with scale and compasses on 

 paper. The continents and islands are made of turf, the sea is gravel, and 

 the boundary is a border of box at particular places on this novel ocean of 

 gravel. Posts are set up, indicating trade-winds, currents, etc. London 

 News. 



CONSUMPTION OF GAS SMOKE. 



A little invention for the prevention of gas smoke has recently been pa- 

 tented and introduced in London. It consists merely of an ornamental cir- 

 clet of metal, across which is stretched a sort of sieve of fine platina wire, 

 and it is intended to be placed as a cover on the top of the globe or chim- 

 ney. The result is most remarkable. The smoke appears to be instantly 

 annihilated, and the flame both increases in bulk and becomes brighter and 

 more clear. The photogenic improvement is stated to be from twenty-five 

 to thirty per cent. All effluvium from the gas is destroyed, and the discolor- 

 ation of the ceiling and decorations of the room prevented by the use of 

 this simple apparatus. London Literary Gazette. 



PATENT GAS REGULATOR. 



Mr. Herbert "W. Hart, of Birmingham, England, gas engineer, has intro- 

 duced a method of regulating the pressure of gas in its transmission to gas 

 burners, by the introduction of a regulator in the main pipes through which 

 the gas passes, whereby a steady and nearly uniform pressure is maintained 

 at the burners, whatever may be the pressure from the source of supply. 

 This regulator consists of a chamber filled with fibrous material, so that the 

 gas in its passage must pass through or amongst the fibres. In preparing 

 this permeable fibrous body, the patentee takes layers of felt, or other fibrous 

 material, and makes up a sufficient thickness according to the initial pres- 



