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Common terms and phrases
adjustment aneroid apparent artificial horizon astronomical azimuth barometer boiling camp centre chronometer circle clamp computed correct cosec cosine declination Diff difference Dist east Equal Altitudes especially Fahr feet fixed give grains Greenwich Greenwich mean height hill horizon glass hour angle inches Index error instrument intersection interval L₁ latitude Leith Hill limb longitude lunar lunar distances mean measured meridian altitude meridian passage method miles moon moon's Nautical Almanac object obtained paces pairs of observations parallel Plane Table plates position prismatic compass reflected image refraction result right ascension round scale screw sextant side Sidereal sine skin specimens star star's station subtract sun's survey TABLE XVI.-Nat taken telescope temperature theodolite thermometer traveller triangles tribes tropical true bearing tube vernier-plate verniers vertical watch zenith distance ΙΟ
Popular passages
Page 209 - In all cases it is best to procure the strongest possible, being less bulky, and water can always be obtained to reduce the strength to the requisite amount. When the spirit sold retail by the natives is not sufficiently strong, by visiting the distillery the traveller can often obtain the first runnings (the strongest) of the still, which will be stronger than he requires undiluted. The spirit used should be reduced to about proof, and the traveller should always be provided with an alcoholometer....
Page 33 - Adjust the horizon-glass so that the two images coincide when the reflected passes the direct in moving the arm. 3. To make the axis of the telescope parallel to the plane of the arc.
Page 181 - When the boiling point at the upper station alone is observed, we may assume 30-00 inches, or a little less, as the average height of the barometer at the level of the sea. The altitude of the upper station is then at once approximately obtained from the tables.
Page 8 - The logarithm of the quotient of two positive numbers is found by subtracting the logarithm of the divisor from the logarithm of the dividend. (6) The logarithm of a power of a positive number is found by multiplying the logarithm of the number by the exponent of the power. For, N" = (oT)
Page 205 - Where wood is scarce, as in the interior of Africa, boxes may be made of the skins of antelopes, or other large animals, by stretching them when newly stripped from the animal over a square framework of sticks, and sewing up the edges after being dried in the sun ; they make excellent packingcases. With regard to reptiles and fishes, I cannot do better than quote the following remarks sent to me by Mr.
Page 216 - ... metals) is not to be recommended to the traveller, if he is not a geologist. Fossils from an unexplored country are of little use unless the nature and order of superposition of the strata in which they are found can be at the same time investigated. In the cases, however, of recent alluvial strata or the supposed beds of ancient lakes, or deposits in caves, or raised sea-beaches containing shells or bones of vertebrate animals', the traveller will do well to bring away specimens if a good opportunity...
Page 217 - The food of each species should be noticed, and if any change of customary food is observed, owing to the failure of the supply, it should be carefully recorded. The use in nature of any peculiar physical conformation of animals, the object of ornamentation, and so forth, should also be investigated whenever opportunity occurs. Any facts relating to the interbreeding in a state of nature of allied varieties, or the converse — that is, the antipathy to intercrossing of allied varieties — would...
Page 45 - Diff. in 1 da. = fi = 3m 55.33« (Quotient) True daily Diff. = 3°> 55.91« Daily rate = .58« gaining. Ans. It is evident that by this method of equal altitudes of a star on the same side of the meridian, the inconvenience of waiting a long time at unsuitable hours during the night for equal altitudes on both sides of the meridian is done away with. The observer may, instead, take observations on one night or evening and repeat it 2, 5, or 8 days afterwards. The result will be just as accurate and...
Page 202 - In most tropical countries the species found in open and semi-cultivated places are much less interesting than those inhabiting the interior of the forests, and it generally happens that the few handsome kinds which attract the attention of the natives are species well known in European museums. In botany, a traveller, if obliged to restrict his collecting, might confine himself to those plants which are remarkable for their economical uses ; always taking care to identify the flowers of the tree...
Page 202 - ... natives are species well known in European museums. In botany, a traveller, if obliged to restrict his collecting, might confine himself to those plants which are remarkable for their economical uses ; always taking care to identify the flowers of the tree or shrub whose root, bark, leaves, wood, &c., are used by the natives, and preserving a few specimens of them. But, if he is the first to ascend any high mountain, he should make as general a collection of the flowering plants as possible,...