INDEX. 



319 



vantages of, 31 



Machine and a tool, difference between, Mortar, why becomes hard, 33 



31 

 rhat Is a, 31 



,31 



Machinery does not create power, 

 Magnet, directive power of, 296 



what occurs when one is broken, 



293 

 Magnets, horse-shoe, 293 



how constructed, 297 

 natural, where found, 295 

 weights, great, lifted by, ? 

 Magnetism, communicated by contact, 



295 

 connection with electricity, 



295 



Malleability, 11 

 Man alone capable of enduring all tempe- 

 ratures, 143 

 method in which he can exert the 



greatest strength, 33 

 on a church spire, why scorns very 



small, 251 



shrinks when starved, 233 

 Maps, coast survey, how produced, 294 

 Mastich, or mastic, 40 

 Matches, how ignited by friction, 141 

 Materials, strength of, 36 



illustrations of, 36 

 Matter defined, 3 



evidence of its existence, 3 



limits to the division of, 5 



particle of, 5 



properties of, 4 



the strongest form in which it can 



be arranged, 36, 37 

 Miasm, or miasmata, 311 

 Milk boils more readily than water, 155 

 Mirror, how we see ourselves in a, 245 



why images appear behind a, 247 



Moon, why seems a flat surface, 251 



why seems larger than tho stare, 



Mortare, composition of, 38 



Mortising, what is, 42 



Motion, 22 



Mountains, distant, why appear 



bluo, 



high, why covered with snow, 



105 



Mountain tops, why cold, 172 

 Muriatic acid, 304 

 Muscular energy, how exerted, 33 

 Music, scale of, 121 

 Musical instruments, how occasion sound, 



sounds, what are, 120 



N 



Nails in old houses, why loose, 187 

 Near-sightedness, cause of, 264 



how remedied, 265 

 Needle, magnetic, 296 

 Negro's skin never blisters from the sun, 



174 



Nitric acid, 304 



Nitrogen, its properties and uses, 205 

 what is, 205 



Objects, how we judge of the sizo and 



position of, 250 

 Ocean, colors of animals in, 272 



depth to which light penetrates, 



Odors, 307 



Oersted, Prof., his discovery, 299 



Mirrors, 245 Oil and water, why not mix, 193 



Mist and fog, distinction between, 89 Opaque bodies, 261 

 Meat, how preserved by smoking, 303 Orders in architecture, 45 



when tough, 303 'Owls, why see in the dark, 267 



Medicines, prescription by drops unsafe, Oxygen, now much required per hour, 



Mercury, freezes at what temperature, 



191 

 of a barometer, why sinks in fine Oxidation, what is, 220 



weather, 104 

 when freezes, 134 

 Metals, why melted by fire, 192 

 Meteorites, how supposed to originate, 96 



what are, 94 



Meteorology, what is, 74 

 Mist and fog, why vanish at sunrise, 164 

 Mist, on windows, cause of, 87 



209 



its properties and uses, 205 

 what is, 205 



Paint, in tho vicinity of sowers, why dis- 

 colored, 304 



how preserves wood, 152 

 Paints, lead, when dangerous, 310 



Mixture and solution, difference between, Paper, blotting, why absorbs ink, 66 



193 

 Moon, lisht of, seems to make a path in 



'the water, 249 

 influence of, on the weather, 111 



light, how occasions putrefaction, Pendulums, compensating, 187 



112 



why appears largo on the borkon, 

 269 



writing, why will not absorb ink, 



66 



Paste, adhesiveness due to irhat, 303 

 Pedestal, what is a, 46 



length of, that beats seconds, 



29 

 what fa a, 29 



