*77 



MANUSCRIPTS. 



MAP. 



478 





capable of affording nourishment, until the tannin is got rid of by 

 fermentation, when plants, as may be observed in bark-beds, root very 

 readily in tan. Inert peaty matter is a substance of the same kind, 

 and will remain for years exposed to air and water without under- 

 going change. When peat becomes inert, it is in vain to attempt 

 to grow any sort of plant in it ; but nothing is more certain than 

 that if drained of stagnant moisture and mixed with liir^ and 

 dung, it will become very fertile for most crops. It often happens 

 that peat or boij-mouM, frequently procured at a great expense for 

 American plants, becomes inert ; in such cases, a good result would be 

 obtained by turning out the peat and mixing it up in a heap with a 

 quantity of leaves or fresh litter sufficient to promote a moderate 

 degree of fermentation; then, as in the case of tan, it will afford 

 nourishment, and will, from a state-of uselessness, become valuable. 



Of mineral manures lime is the most useful. It is not recommended 

 for soils that contain a large proportion of soluble vegetable matter ; 

 but it produces excellent effects in such as abound in inert vegetable 

 fibre Gypsum, which is found in the ashes of grasses, proves a, 

 manure for lann-. 



Common salt is sometimes employed in minute portions ; especially 

 in combination with vegetable matter, in the instance of sea-weeds, in 

 which case it is found of good quality for fruit-trees and kitchen- 

 garden crops ; but vegetable life is certainly destroyed by it, if applied 

 in any considerable quantity. Exceptions may be noticed in the case 

 of marine plants; the samphire for example, requires it when 

 cultivated in inland districts ; and this is also true of the vegetable 

 inhabitants of the great salt plains of Asia. Wood-ashes, which consist 

 principally of vegetable alkali united to carbonic acid, are a good 

 manure, but of short duration, and they leave peaty soil in a worse 

 state than before their application. The application of dung and lime, 

 of composts of clay, marl, scourings of ditches, &c., would render peat 

 permanently fertile, more especially when draining is judiciously 

 attended to. 



MANUSCRIPTS. [PALEOGRAPHY.] 



MAP (Latin, muftia, a napkin ; French, mappemonde, a map of the 

 world). A map is a representation of the surface of a sphere, or a 

 portion of a sphere, on a plane. The name, however, is commonly 

 applied to those plane drawings which represent the form, extent, 

 position, and other particulars of the various countries of the earth. 



Maps, or delineations resembling them, we may reasonably con- 

 clude were coeval with the earliest geographic knowledge; but it 

 is not possible to fix the time of the first attempts to construct 

 maps. The geographical knowledge of the Greeks, as exhibited 

 in the Homeric poems, comprehended only a small part of Europe, 

 Asia, and Africa, and there is not the slightest allusion in them 

 to any mode of delineating or representing the surface of a country. 

 In their maritime adventures the Greeks are said to have been 

 assisted by the nautical maps of the Phoenicians ; but however this 

 may be, we have no account of anything deserving the name of maps 

 before those of Anaximander the Milesian, who is alleged to have been 

 the tirst to construct a map of the world. Itinerary maps of the places 

 of encampment were almost indispensable to the commanders of 

 armies ; Diognetus and Beton are mentioned ( Pliny, ' Nat. Hist.' vi., 

 17) as the surveyors of the marches of Alexander, who was very care- 

 ful in examining the measures of his surveyors, and in obtaining 

 his descriptions from the most skilful persons. The science of geo- 

 graphy made rapid advances under Eratosthenes [ERATOSTHENKS, in 

 Bio<;. Div. ; GEOGRAPHY], who had the great merit of reducing geo- 

 graphy to a regular system, and of founding it upon solid principles. 

 He introduced into his map a' regular parallel of latitude, which he 

 accomplished by tracing a line over certain places whose longest day 

 was observed to be of the same length. This parallel extended from 

 the Strait of Gibraltar to the mountains of India, passing through the 

 island of Rhodes ; and from its central position with respect to the 

 principal ancient nations, it became a standard of reference in the maps 

 of this period. Succeeding geographers made many attempts to 

 determine thelongitudeof places by measurements of this line, but with 

 no great success. Eratosthenes, in addition to the parallel above men- 

 tioned and other parallels, undertook to draw a meridian from Meroe 

 ;h Syene to Alexandria (' Strabo,' ii. 114), and also to determine 

 the earth's circumference by the actual measurement of a portion of 

 one of its gnat circles. These discoveries and improvements very 

 materially affected the dimensions of all the ancient maps ; and from 

 this time the connection between astronomy and geography was so far 

 eetablixhed as to ensure an advantage to the latter by every advance of 

 the former. This was eminently the case in the discoveries of Hip- 

 parchus, who fixed the construction of maps on a mathematical basis, 

 and enabled the geographer to lay down his latitudes and longitudes 

 "rtain principles. 



To Strabo we are chiefly indebted for our information respecting the 

 state of geography in the Augustan age. But the extent of the earth's 

 surface known to this writer dots not very much exceed that which 

 was known to Herodotus four centuries earlier. His map of the world 

 exhibits some remarkable errors. He supposed the Pyrenees to run 

 north and south ; cuts off the projecting province of Brittany from 

 France, places Ireland not to the west but to the north of Britain, anil 

 makes the Caspian communicate with the northern ocean though 

 ' 'dotu.i had accurately described it an a lake. 



The Roman Itineraries show that their surveys were made with con- 

 siderable care, although there are no traces of mathematical geography 

 in those which have been handed down to us, the chief object in view 

 being the clear direction of the march of their armies; All the pro- 

 vinces of the Roman empire had been surveyed when Ptolemy com- 

 posed his system of geography, which has happily been preserved to 

 us. It is n it so much to his more perfect acquaintance with the earth 

 that Ptolemy owes his reputation as a geographer, as to his giving 

 solidity and unity to the science by fixing its unconnected details 

 on a mathematical basis and carrying into full practice and to greater 

 perfection the system of latitudes and longitudes of Hipparclms, 

 whose invention had been much neglected for upwards of 250 

 years. 



It seems not improbable that the maps found in the MSS. of Ptolemy 

 are really copies of, or derived from, original maps constructed by him 

 or under his care. [AGATHOD.EMON, in Bioo. Div.] 



The geography of the Arabians is but imperfectly known. Their 

 most eminent geographer Edrisi or Eldrisi, who lived about the middle 

 of the 12th century, divided the world into seven climates ironi the 

 equator northward, and each climate was again divided into eleven 

 equal parts, from the western coast of Africa to the eastern coast of 

 Asia, the inconvenience of which arrangement is very obvious. 



Towards the middle of the 17th century several astronomers under- 

 took to observe eclipses of the moon, with a view of correcting the 

 errors in the longitude of places. These observations, however, were 

 so discordant as to lead to no satisfactory result. Galileo, by the dis- 

 covery of the eclipses of the satellites of Jupiter, introduced a more 

 certain method, which was rendered available by means of the simul- 

 taneous observations of Picard and Cassini at the observatories of 

 Uraniburg and Paris. 



Picard and De Lahire were then immediately employed in correcting 

 the map of France, and from this i eriod our maps have rapidly 

 improved. The great perfection to which timekeepers have been 

 brought, and the obvious application of these machines to the deter- 

 mination of the longitude, have greatly contributed to their accuracy. 

 But notwithstanding the advanced state of our astronomical and 

 geographical knowledge, and the science and skill displayed . in our 

 great national and other surveys, we may, with Dr. Blair, regard maps 

 as works in progress always unfinished, and still waiting the cor- 

 rections to be supplied by the science and enterprise of succeeding 

 ages. 



Having thus briefly sketched the progress of map-making, we pro- 

 ceed to give a general outline of the application and construction 

 of map-. 



On the Nature and Construction of Maps. Maps, being plane repre- 

 sentations of the surface of a sphere, may be obviously applied to 

 various purposes ; hence we not only have terrestrial maps to repre- 

 sent the surface of the earth, but celestial or astronomical maps to 

 represent the sphere of the heavens ; and these general distinctions 

 have again their subdivisions. 



There are two kinds of terrestrial maps geographic or land maps, 

 and liydrographie or sea maps : we shall confine our attention princi- 

 pally to the former; the latter, which are usually called charts, having 

 been already described. [CHART.] 



Geographic maps, as already noticed, are those which represent the 

 forms and dimensions of the several parts of the earth, with their 

 relative situations and the positions of the cities, mountains, rivers, 

 &c., comprised within their limits. They may comprehend the whole 

 earth, or one of its larger divisions, or a single district, and are called 

 maps of the world, general maps, or particular maps accordingly. If 

 they give the nature of the ground, the roa ,s, buildings, &c., in detail, 

 they become topographic maps, which, necessarily embracing a very 

 small extent of country, are not usually referred to any spherical pro- 

 jection, but are represented as geometric planes, the objects in them 

 occupying the positions severally assigned to them by the trigono- 

 metrical operations of the survey. The same distinction is made in 

 charts of small bays and harbours. In either ot these eases they are 

 called plans. 



When maps of the earth are made to illustrate any of the sciences, 

 they are distinguished from geographic maps, properly so called, and 

 bear their own peculiar names, as geological, or mineralogical, or 

 botanical maps. A collection of such maps is called a physical atlas : 

 suoh are the admirable atlases published by Berghaus, Johnston, and 

 Petermann, in which the results of the investigations in geology, 

 geography, hydrography, magnetism, meteorology, &c., are presented 

 distinctly to the eye. 



Of late years the leading governments of Europe have published 

 maps showing, on a comparatively large scale, the results of elaborate 

 trigonometrical surveys of the several countries : the maps of Austria 

 and France are beautiful examples. In England, the results of the 

 Ordnance Survey of a large portion of Great Britain and Ireland have 

 been published in a series of admirable maps, at an extremely moderate 

 price. The chief drawback is that, in the long intervals between the 

 publication of the different portions, material alterations are taking 

 place with extraordinary rapidity. New railways are made ; old roads 

 are stepped up, and new ones opened ; new towns spring up round 

 railway stations, and villages become towns. Perhaps no mode of 

 publication could be adopted to keep pace with these changes ; and 



