An Elementary Treatise on Steam: More Particularly as Applicable to the Purposes of Navigation with a Familiar Description of the Engine

Front Cover
G. Poore, 1837 - 259 pages
 

Other editions - View all

Common terms and phrases

Popular passages

Page 93 - Since all matter may be made to fill a smaller volume by cooling, it is evident that the particles of matter must have space between them, and since every body can communicate the power of expansion to a body of a lower temperature ; that is, can give an expansive motion to its particles, it is a probable inference, that its own particles are possessed of motion : but as there is no change in the position of its parts, as long as its temperature is uniform, the motion, if it...
Page 94 - ... lower temperature, that is, can give an expansive motion to its particles, it is a probable inference that its own particles are possessed of motion; but as there is no change in the position of its parts as long as its temperature is uniform, the motion, if it exist, must be a vibratory or undulatory motion, or a motion of the particles round their axes, or a motion of particles round each other.
Page viii - ... mysteries known only to adepts ; to surprise and astonish by results, but conceal processes. The character of science is the direct contrary. It delights to lay itself open to inquiry, and is not satisfied with its conclusions, till it can make the road to them broad and beaten : and in its applications it preserves the same character ; its whole aim being to strip away all technical mystery, to illuminate every dark recess, and to gain free access to all processes, with a view to improve them...
Page 93 - The immediate cause of the phenomena of heat then is motion, and the laws of its communication are precisely the same, as the laws of the communication of motion.
Page 106 - It has been found that the heat absorbed by vaporization is always less, the higher the temperature at which the ebullition takes place ; and less, by the same amount as the temperature of ebullition is increased. Thus, if water boil at 312°, the heat absorbed in ebullition will be less by 100° than if it boiled at 212° ; and again, if water be boiled under a diminished pressure, at 112°, the heat absorbed in vaporization will be...
Page 175 - Some of our best builders place this point only one third of the length from the stem. Abstractly, it would seem most important that the bow should be adapted to divide the water with the least possible resistance; but experience has proved that it is far more essential to facilitate the escape of the displaced water along the side of the vessel; for when once a passage is opened for the ship, the fluid tends to reunite abaft the point of greatest breadth, where, instead of offering resistance, it...
Page 53 - The velocity of water flowing out of a horizontal aperture, is as the square root of the height of the head of the water. — That is, the pressure, and consequently the height, is as the square of the velocity ; for, the quantity flowing out in any short time is as the velocity...
Page viii - The whole tendency of empirical art is to bury itself in technicalities, and to place its pride in particular short cuts and mysteries known only to adepts: to surprise and astonish by results, but conceal processes. The character of science is the direct contrary. It delights to lay itself open to...
Page 145 - Caking coal gives out a great quantity of heat, and, with attention, burns a long time; consequently, where it can be procured at a reasonable price, it is commonly preferred. From the trials of Mr. Watt, it appears that a bushel of Newcastle coals, which weigh, on an average, eighty-four pounds, will convert from eight to twelve cubic feet of water into steam, from the mean temperature of the atmosphere; and that a bushel of Swansea coal will produce an equal effect. Dr. Black states to the effect,...
Page 95 - ... intermixture, and many other modes, fluid particles impart heat to each other ; and experiments have been instituted, which prove the actual descent of heat through fluids by communication from one stratum to another. But unquestionably this communication is amazingly difficult and slow. We are hence led to conceive, that it is an actual contact of particles which in the solid condition facilitates the transmission of heat so speedily from point to point thro-igh their mass.

Bibliographic information