Comentarios de la gente - Escribir un comentario
No encontramos ningún comentario en los lugares habituales.
Otras ediciones - Ver todas
acid action alloy alumina aluminium ammonia amount amylene apparatus appears atmosphere bodies boiler British Association carbon carbonic acid centre chemical chloride chromium coal collodion process color combustion condenser conservation of force containing copper crystals cylinder diameter dissolved distance earth effect electricity experiments fact feet flame fluid furnace glass gold gravity gutta percha heat hundred hydrogen inches invention iron length light lime liquid machine magnetic manganese mass matter means mechanical metal miles motion nature nitric acid observations obtained ordinary oxide paper particles passed perpetual motion phenomena placed plants plate portion potash pounds prepared present pressure principle produced Prof Professor proportion quantity recently result salt shells silicate Silurian silver solar solid solution specimens steam substance sugar sulphuric sulphuric acid surface temperature tion tube tungstic acid vapor vessel weight wire zinc zodiacal light
Página 427 - ... merchant, mechanic and laborer will find it one of the choicest companions of the hours of relaxation. " Whatever be the mood of one's mind, and however limited the time for reading, in the almost endless variety and great brevity of the articles he can find something to suit his feelings, which he can begin and end at once.
Página 118 - Droz: which latter, when performing, followed its hands with its eyes, and at the conclusion of the piece bowed courteously to the audience. That men like those mentioned, whose talent might bear comparison with the most inventive heads of the present age, should spend so much time in the construction of these figures, which we at present regard as the merest trifles, would be incomprehensible, if they had not hoped in solemn earnest to solve a great problem.
Página 134 - ... continuation of life is dependent on the consumption of nutritive materials: these are combustible substances, which, after digestion and being passed into the blood, actually undergo a slow combustion, and finally enter into almost the same combinations with the oxygen of the atmosphere that are produced in an open fire. As the quantity of heat generated by combustion is independent of the duration of the combustion and the steps in which it occurs, we can calculate from the mass of the consumed...
Página 195 - ... probably quite large enough to supply the wants of the human family to the end of its sojourn here. It has been calculated that an amount of condensation, which would diminish the diameter of the Sun by only the ten-thousandth part, would suffice to restore the heat emitted in 2000 years.
Página 126 - I have long held an opinion, almost amounting to conviction, in common I believe with many other lovers of natural knowledge, that the various forms under which the forces of matter are made manifest have one common origin; or, in other words, are so directly related and mutually dependent, that they are convertible, as it were, one into another, and possess equivalents of power in their action.
Página 126 - ... and having first made the acquaintance of Joule's experiments at the end of my investigation, followed the same path. I endeavoured to ascertain all the relations between the different natural processes, which followed from our regarding them from the above point of view. My inquiry was made public in 1847, in a small pamphlet bearing the title, "On the Conservation of Force.
Página 121 - The expenditure of force will in the first place, other circumstances being equal, be proportional to the weight of the hammer; it will, for example, be double when the weight of the hammer is doubled. But the action of the hammer depends not upon its weight alone, but also upon the height from which it falls. If it falls through two feet, it will produce a greater effect than if it falls through only one foot. It is, however, clear that if the machine, with a certain expenditure of force, lifts...
Página 131 - By the centrifugal force which must act most energetically in the neighborhood of the equator of the nebulous sphere, masses could from time to time be torn away, which afterwards would continue their courses separate from the main mass, forming themselves into single planets, or, similar to the great original sphere, into planets with satellites and rings, until finally the principal mass condensed itself into the sun. With regard to the origin of heat and light, this view gives us no information....
Página 126 - Light, heat, electricity, magnetism, motion, and chemical affinity, are all convertible material affections ; assuming either as the cause, one of the others will be the effect ; thus heat may be said to produce electricity, electricity to produce heat, magnetism to produce electricity, electricity magnetism, and so of the rest.