## The Mechanical Principles of Engineering and Architecture |

### Contents

91 | |

106 | |

112 | |

121 | |

130 | |

142 | |

143 | |

148 | |

154 | |

160 | |

166 | |

175 | |

194 | |

202 | |

213 | |

227 | |

234 | |

241 | |

257 | |

379 | |

387 | |

396 | |

400 | |

440 | |

446 | |

454 | |

508 | |

518 | |

527 | |

540 | |

553 | |

637 | |

653 | |

675 | |

683 | |

691 | |

698 | |

### Other editions - View all

### Common terms and phrases

a₁ angle of resistance angular velocity arch axes axis beam body bordering upon motion capstan centre of gravity circumference co-efficient conical surfaces cord corresponding crank crank arm cubic foot curve cylinder deflexion described determined dimensions direction distance ditto driven wheel elongation epicycloidal equal equation equilibrium evident exceedingly small extrados fly-wheel forces friction given horizontal hypocycloidal intersect involute lamina length limiting angle line of centres line of resistance load machine modulus moment of inertia moving n₁ n₂ neutral line numbers of teeth observing obtain P₁ P₂ parallel passing perpendicular pitch circle plane point of application point of contact portion position pressures applied pulley radii radius repre respect revolution revolve rupture screw space stability supposed surfaces of contact taken to represent tension tion tooth U₁ vertical vis viva voussoirs wall weight whence it follows whilst whole

### Popular passages

Page vii - Moral State and Moral Prospects of Society, being the substance of a course of lectures delivered to the students of the Theological Hall in Edinburgh, — " We know," says this distinguished philosopher, " that there is a mighty force of sentiment and natural affection arrayed against the law of primogeniture But here is the way in which we would appease these feelings, and make compensation for the violence done...

Page 22 - In the same manner it may be shown that the centre of gravity of the triangle is in the line CE ; therefore, the centre of gravity is at the intersection G of these lines.

Page 6 - The sum of the moments of a number of coplanar forces round any point is equal to the moment of their resultant about that point. Let P and Q be two forces.

Page 667 - ... of its extension will therefore be to cause the lower of the two bodies to descend whilst the higher remains at rest. The converse of this will result from contraction ; for when the contractile force becomes sufficient to pull the upper body down the plane it will not have become sufficient to pull the lower up it. Thus, in the contraction of the substance which intervenes between the two bodies, the lower will remain at rest whilst the upper descends. As often, then, as the expansion and contraction...

Page 566 - From this we see that two parallel forces acting hi the same direction, 1st, have a resultant which is equal to their sum ; 2nd, that the direction of this resultant is parallel to that of the forces ; 3d, that it divides the line joining the points of application of the two forces into parts reciprocally proportional to the forces ; 4th, that either force is to the resultant as the portion of the line between the resultant and the other force is to the total distance between the points of application...

Page 674 - Mr. Hopkins placed a mass of rough ice, confined by a square frame or bottomless box, upon a roughly chiselled flag-stone, which he then inclined at a small angle ; and found that a slow but uniform motion was produced, when even it was placed at an inconsiderable slope.

Page 517 - ... distribution of the material is not such as that the compressed and extended sides would yield together, the strongest form of section is not attained. Hence it is apparent that the strongest form of the section collects the greater quantity of the material on the compressed or the extended side of the beam, according as the resistance of the material to compression or to extension is the less. Where the material of the beam is cast iron, whose resistance to extension is greatly less than its...

Page 123 - When no unguent is interposed, the friction of any two surfaces, whether of quiescence or of motion, is directly proportional to the force with which they are pressed perpendicularly together ; so that for any two given surfaces of contact there is a constant ratio of the friction to the perpendicular pressure of the one surface upon the other. Whilst this ratio is thus the same for the same surfaces of contact, it is different for different surfaces of contact. The particular value of...

Page 694 - No one who has studied art in Venice will go through this book without such pleasure as belongs to a revival of some of his warmest admirations, and the refreshment of his most delicious associations. It is full of fine things, and of true things/

Page 425 - BD, in which case no resistance can be opposed to the resultant force acting in that point ; or, thirdly, the point Q lying within the surface BD, we may destroy the equilibrium by causing the line of resistance to cut the surface of the mass somewhere between that point and P. Let us suppose the limits of the variation of P within which the first two conditions are satisfied, to be known ; and varying it, within those limits, let us consider what may be its least and greatest values so as to satisfy...