What people are saying - Write a review
We haven't found any reviews in the usual places.
Other editions - View all
angle appear atmosphere attraction axis ball body bottom called centre of gravity comet concave conductor consequently CONVERSATION convex convex lens copper cubic foot cylinder descend diameter direction distance diurnal motion earth eclipse electricity equal equator experiment fall feet fixed stars fluid force fulcrum glass globe grains greater heat heavens horizon hydrometer inches inclined plane iron Jupiter kind length lens less lever Leyden jar light machine magnet means mechanical powers mercury metal millions of miles minutes moon motion move multiplied object observe orbit ounces papa pass pendulum perpendicular piece pipe piston planets pole pound pound weight pressure principle produced proportion pulley quantity quicksilver rays refracting telescope refraction retina rise rotation round screw seen side silver space specific gravity square substance suppose surface tube valve velocity vessel weight wire
Page 208 - ... is forced into the condenser by the pressure of the atmosphere on the surface of the water supply outside.
Page 344 - It will now be obvious why it is impossible for the artist to give a faithful representation of any near solid object, that is, to produce a painting which shall not be distinguished in the mind from the object itself.
Page 329 - ... as the angle of reflection is always equal to the angle of incidence, the image for any point can be seen only in the reflected ray prolonged.
Page 422 - Reaumur, that he felt himself struck in his arms, shoulders, and breast, so that he lost his breath, and was two whole days before he recovered from the effects of the blow.
Page 288 - ... will slide on towards the narrow end, less or more, according to the degree of heat to which it has been exposed*. Each degree of Mr. Wedgewood's thermometer answers to 130 degrees of Fahrenheit, and he begins his scale from red heat fully visible in daylight, which he finds to be equal to 1077° of Fahrenheit's scale, if it could be carried so high.
Page 330 - When the object is more remote from the mirror than its centre of concavity C, the image will be less than the object, and between the object and...
Page 44 - ... to his strength; which is done by so dividing the beam they pull, that the point of traction may be as much nearer to the stronger horse than to the weaker, as the strength of the former exceeds that of the latter. To this kind of lever may be reduced...
Page 97 - I do: twice only in the year, a line drawn from the centre of the sun to that of the earth passes through those points where the equator and ecliptic cross one another; at all other times, it passes through some other part of that oblique circle, which is represented on the globe by the ecliptic line.
Page viii - Powers. Certainly no species of knowledge is better suited to the taste and capacity of youth, and yet it seldom forms a part of early instruction. Every body talks of the lever, the wedge, and the pulley, but most people perceive, that the notions which they have of their respective uses, are unsatisfactory, and indistinct ; and many endeavour, at a late period of life, to acquire a scientific and exact knowledge of the effects that are produced by implements which are in every body's hands, or...