Other editions - View all
abundance according advantages agricultural animals annual arts ascer ascertain atmosphere attention banks Basalt calcareous causes cavern circumstances civilized clay climate coal colour commerce construction cultivated degree deposits depth direction distance earth effect employed exist extent felspar fish foreign formation fossils Gneiss greater Gypsum height hornblende Hygrometer importance industry influence inhabitants instrument interest Kaolin labour lake land latter laws less limestone manner manufacturing mass means measure ment metals Mica mineral mode moral mountains nations nature necessary nerally notice number of persons objects observations obtained operations particular peat places plants principal produce proportion quantity quartz racter rain reason regarding regulations remarkable river roads rocks salt sand sandstone Schistose sheep's sorrel shells situation soil sometimes specific gravity stones strata stratum sufficient surface temperature thermometer thing tion traveller tufas various vegetable veins viviparous winds worthy zodiacal light
Page 91 - Sometimes this and the Cirro-cumulus appear together in the sky, and even alternate with each other in the same cloud; when the different evolutions which ensue...
Page 108 - ... 3. The observations should, if possible, all be made by one person ; but as this may often be impracticable, the principal observer should take care to instruct one or more of his family how to do it, and should satisfy himself by many trials that they observe alike. 4. The entries in the register should be made at the time of observation, and the numbers entered should be those actually read off on the respective scales of each instrument, on no account applying to them previous to entry any...
Page 543 - SO'OO inches as the average height of the barometer at the level of the sea (which is however too much), the altitude of the upper station is at once obtained by inspection of Table I, correcting for temperature of the stratum of air traversed by table II.
Page 543 - When the boiling point at the upper station alone is observed, and for the lower the level of the sea or the register of a distinct barometer is taken, then the barometric reading had better be converted into feet, by the usual method of subtracting its logarithm from 1•47712 (log. of 30 inches) and multiplying by '0006, as the differences in the column of " barometer" vary more rapidly than those in the "feet
Page 86 - The usual course of periodical winds, or such as remarkably prevail during certain seasons, with the law of their diurnal progress, both as to direction and intensity ; at what hours, and by what degrees they commence, attain their maximum, and subside ; and through what points of the compass they run in so doing.
Page 90 - The Rain cloud. A cloud, or system of clouds from which rain is falling. It is a horizontal sheet, above which the Cirrus spreads, while the Cumulus enters it laterally and from beneath.
Page 91 - On the return of the sun, the level surface of this cloud begins to put on the appearance of cumulus, the whole at the same time separating from the ground. The continuity is next destroyed, and the cloud ascends and evaporates, or passes off with the appearance of the nascent cumulus.
Page 539 - ... above the bottom of the pot. Violent ebullition was continued for ten minutes or a quarter of an hour, and the height of the mercury was repeatedly ascertained during that time, and the temperature of the air was noticed. Similar operations were repeated with a second thermometer, for it is never safe to rely upon one instrument.
Page 108 - All these and the like corrections, being matter of calculation and reasoning from other observations, are to be reserved till the final discussion of the series, and for separate determination and statement. 5. If copies be taken of the registers, they should be carefully compared with the originals by two persons, one reading aloud from the original and the other attending to the copy, and then exchanging parts, a process always advisable wherever great masses of figures are required to be correctly...
Page 472 - A cubical box of strong tin or zinc, exactly 10 inches by the side, open above, receives at an inch below its edge a funnel, sloping to a small hole in the centre. On one of the lateral edges of the box, close to the top of the cavity, is soldered a short pipe, in which a cork is fitted. The whole should be well painted. The water which enters this...