SCIENCE 



lEntered at the Post-Offlce of New York, N.Y., as Second-Class Matter,] 



A WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES 



Eighth Year. 

 Vol. XV. No. 364. 



NEW YORK, January 24, 1890. 



Single Copies, Ten Cents. 

 (3.50 Per Year, in Advance. 



A STEEL PRESSURE-BLOWER. 

 The annexed engraving illustrates a steel pressure- blower on a 

 recently perfected pattern of adjustable bed with countershaft, de- 

 signed and consttucted with special reference to high-pressure 

 duty, such as supplying blast for cupola furnaces, forge- fires, and 

 sand-blast machines, also for forcing air long distances. By means 

 of a tighlening-screw, the blower may be moved upon the bed 

 while running at full speed, taking up any slack, giving both belts 

 a uniform tension, which is regulated at the will of the operator. 

 This is a very important point in preventing Lhe inconvenience and 

 loss incurred by a stoppage during heat when blowers are used for 

 cupola purposes. By the use of this adjusting device, a great sav- 

 ing'Js made in the wear and tear of belts, for a simple turn or two 



stretches with immunity from heat or cutting. A distinguishing 

 feature of these blowers is the solid case, the peripheral portion of 

 the shell being cast in one solid piece, thus dispensing with objec- 

 tionable joints. The journals are long and heavy, and have cap- 

 bearings secured by bolts held firmly in place by lock-nuts. It is 

 made by the Buffalo Forge Company, Buffalo, N.Y. 



THE TOBACCO-PLANT. 



After the cereals, there is perhaps no plant so extensively cul- 

 tivated and utilized as the tobacco-plant. It is grown and em- 

 ployed as a narcotic in almost every country of the world, and it 

 has been calculated that one-fourth of the human family use it. 



A STEEL PRESSURE-BLOWER. 



of the nut on the adjusting-screw, and a retightening of the hold- 

 ing-down bolts, take but a moment, and accomplish the same end 

 as relacing the bells, which usually is put off until the belt will 

 run no longer on account of slack. Special attention should be 

 directed to pressure-blower belts, on account of the high rate of 

 speed at which they must necessarily run ; and absolutely perfect 

 alignment of the countershaft with the blower is essential in order 

 to secure smooth running and even tracking, as well as to avoid 

 undue wear of belts by slipping. 



A telescopic mouth-piece is employed on this blower, in order 

 that the piping may not be disarranged in moving the machine on 

 the bed, and the countershaft is long enough to carry tight and 

 loose pulleys for the main driving-belt. A self-oiling device fitted 

 to the countershaft enables it to be run at high speeds for long 



At the Colonial Exhibition in London, according to the Journal 

 of the Society of Arts, the dried leaf and its preparations were 

 shown by India and every one of the British possessions, and the 

 Paris Exhibition has supplemented this display by showing its ex- 

 tensive production in Europe, North and South America, eastern 

 Asia, the Pacific Islands, and the continent of Africa. 



It is somewhat difficult to obtain trustworthy information re- 

 garding the world's trade in tobacco, because so much is used up 

 locally in different countries. It is probable that the total area un- 

 der cultivation is not far short of 6,000,000 acres. For the year 

 1886 certain official returns are available, which show that the 

 United States, India, and Hungary are the largest producers. 



The area under tobacco in acres was, in the L^nited States, 752,- 

 520; India, 641,000 ; Hungary and Austria, 149.46S ; Germany, 



