A Source Book in Geography

Author: Claudius Ptolemy  | Date: 1932

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Ptolemy on the Field of Geography and on Divisions of the Earth

Of the characteristics of the inhabitants of the general climes

The demarcation of national characteristics is established in part by entire parallels and angles, through their position relative to the ecliptic and the sun. For while the region which we inhabit is in one of the northern quarters, the people who live under the more southern parallels, that is, those from the equator to the summer tropic, since they have the sun over their heads and are burned by it, have black skins and thick, woolly hair, are contracted in form and shrunken in stature, are sanguine of nature, and in habits are for the most part savage because their homes are continually oppressed by heat; we call them by the general name Ethiopians. Not only do we see them in this condition, but we likewise observe that their climate and the animals and plants of their region plainly give evidence of this baking by the sun.

Those who live under the more northern parallels, those, I mean, who have the Bears over their heads, since they are far removed from the zodiac and the heat of the sun, are therefore cooled; but because they have a richer share of moisture, which is most nourishing and is not there exhausted by heat, they are white in complexion, straight-haired, tall and well-nourished, and somewhat cold by nature; these too are savage in their habits because their dwelling-places are continually cold. The wintry character of their climate, the size of their plants, and the wildness of their animals are in accord with these qualities. We call these men, too, by a general name, Scythians.

The inhabitants of the region between the summer tropic and the Bears, however, since the sun is neither directly over their heads nor far distant at its noon-day transits, share in the equable temperature of the air, which varies, to be sure, but has no violent changes from heat to cold. They are therefore medium in colouring, of moderate stature, in nature equable, live close together, and are civilized in their habits. The southernmost of them are in general more shrewd and inventive, and better versed in the knowledge of things divine because their zenith is close to the zodiac and to the planets revolving about it. Through this affinity the men themselves are characterized by an activity of the soul which is sagacious, investigative, and fitted for pursuing the sciences specifically called mathematical. Of them, again, the eastern group are more masculine, vigorous of soul, and frank in all things, because one would reasonably assume that the orient partakes of the nature of the sun. This region therefore is diurnal, masculine, and right-handed, even as we observe that among the animals too their right-hand parts are better fitted for strength and vigour. Those to the west are more feminine, softer of soul, and secretive, because this region, again, is lunar, for it is always in the west that the moon emerges and makes its appearance after conjunction. For this reason it appears to be a nocturnai clime, feminine, and, in contrast with the orient, left-handed.

And now in each of these general regions certain special conditions of character and customs naturally ensue. For as likewise, in the case of the climate, even within the regions that in general are reckoned as hot, cold, or temperate, certain localities and countries have special peculiarities of excess or deficiency by reason of their situation, height, lowness, or adjacency; and again, as some peoples are more inclined to horsemanship because theirs is a plain country, or to seamanship because they live close to the sea, or to civilization because of the richness of their soil, so also would one discover special traits in each arising from the natural familiarity of their particular climes with the stars in the signs of the zodiac. These traits, too, would be found generally present, but not in every individual. We must, then, deal with the subject summarily, in so far as it might be of use for the purpose of particular investigations.

In what geography differs from chorography

Geography is a representation in picture of the whole known world together with the phenomena which are contained therein.

It differs from Chorography in that Chorography, selecting certain places from the whole, treats more fully the particulars of each by themselves—even dealing with the smallest conceivable localities, such as harbors, farms, villages, river courses, and such like.

It is the prerogative of Geography to show the known habitable earth as a unit in itself, how it is situated and what is its nature; and it deals with those features likely to be mentioned in a general description of the earth, such as the larger towns and the great cities, the mountain ranges and the principal rivers. Besides these it treats only of features worthy of special note on account of their beauty.

The end of Chorography is to deal separately with a part of the whole, as if one were to paint only the eye or the ear by itself. The task of Geography is to survey the whole in its just proportions, as one would the entire head. For as in an entire painting we must first put in the larger features, and afterward those detailed features which portraits and pictures may require, giving them proportion in relation to one another so that their correct measure apart can be seen by examining them, to note whether they form the whole or a part of the picture. Accordingly therefore it is not unworthy of Chorography, or out of its province, to describe the smallest details of places, while Geography deals only with regions and their general features.

The habitable parts of the earth should be noted rather than the parts which are merely of equal size, especially the provinces or regions and their divisions, the differences between these being rather the more important. Chorography is most concerned with what kind of places those are which it describes, not how large they are in extent. Its concern is to paint a true likeness, and not merely to give exact position and size. Geography looks at the position rather than the quality, noting the relation of distances everywhere, and emulating the art of painting only in some of its major descriptions. Chorography needs an artist, and no one presents it rightly unless he is an artist. Geography does not call for the same requirements, as any one, by means of lines and plain notations can fix positions and draw general outlines. Moreover Chorography does not have need of mathematics, which is an important part of Geography. In Geography one must contemplate the extent of the entire earth, as well as its shape, and its position under the heavens, in order that one may rightly state what are the peculiarities and proportions of the part with which one is dealing, and under what parallel of the celestial sphere it is located, for so one will be able to discuss the length of its days and nights, the stars which are fixed overhead, the stars which move above the horizon, and the stars which never rise above the horizon at all; in short all things having regard to our earthly habitation.

It is the great and the exquisite accomplishment of mathematics to show all these things to the human intelligence so that the sky, too, having a representation of its own character, which, although it can not be seen as moving around us, yet we can look upon it by means of an image as we look upon the earth itself, for the earth being real and very large, and neither wholly nor in part moving around us, yet it can be mapped by the same means as is the sky.

What presuppositions are to be made use of in geography

What Geography aims at, and wherein it differs from Chorography, we have definitely shown in our preceding chapter. But now as we propose to describe our habitable earth, and in order that the description may correspond as far as possible with the earth itself, we consider it fitting at the outset to put forth that which is the first essential, namely, a reference to the history of travel, and to the great store of knowledge obtained from the reports of those who have diligently explored certain regions; whatever concerns either the measurement of the earth geometrically or the observation of the phenomena of fixed localities; whatever relates to the measurement of the earth that can be tested by pure distance calculations to determine how far apart places are situated; and whatever relations to fixed positions can be tested by meteorological instruments for recording shadows. This last is a certain method, and is in no respect doubtful. The other method is less perfect and needs other support, since first of all it is necessary to know in determining the distance between two places, in what direction each place lies from the other; to know how far this place is distant from that, we must also know under what part of the sky each is located, that is, whether each extends toward the north, or, so to speak, toward the rising of the sun (the east), or in some other particular direction. And these facts it is impossible to ascertain without the use of the instruments to which we refer. By the use of these instruments, anywhere and at any time, the position of the meridian line can easily be found, and from this we can ascertain the distances that have been traveled. But when this has been done, the measurement of the number of stadia does not give us sure information, because journeys very rarely are made in a straight line. There being many deviations from a straight course both in land and in sea journeys, it is necessary to conjecture, in the case of a land journey, the nature and the extent of the deviation, and how far it departs from a straight course, and to subtract something from the number of stadia to make the journey a straight one.

Even in sailing the sea the same thing happens, as the wind is never constant throughout the whole voyage. Thus although the distance of the places noted is carefully counted, it does not give us a basis for the determination of the circumference of the whole earth; nor do we ascertain an exact position for the equatorial circle or for the location of the poles.

Distance which is ascertained from an observation of the stars shows accurately all these things, and in addition shows how much of the circumference is intercepted in turn by the parallel circles, and by the meridian circles which are drawn through the places themselves; that is to say, what part of the circumference of parallel circles and of the equatorial circle is intercepted by the meridians, or what part of the meridian circles are intercepted by the parallels and equatorial circle.

After this it will readily be seen how much space lies between the two places themselves on the circumference of the large circle which is drawn through them around the earth. This measurement of stadia obtained from careful calculations does not require a consideration of the parts of the earth traversed in a described journey; for it is enough to suppose that the circuit of the earth itself is divided into as many parts as one desires, and that some of these parts are contained within distances noted on the great circles that gird the earth itself. Dividing the whole circuit of the earth or any part of it noted by our measurements which are known as stadia measurements, is a method not equally convincing. Therefore because of this fact alone it has been found necessary to take a certain part of the circumference of a very large celestial circle, and by determining the ratio of this part to the whole of the circle, and by counting the number of stadia contained in the given distance on the earth, one can measure the stadia circumference of the globe.

When we grant that it has been demonstrated by mathematics that the surface of the land and water is in its entirety a sphere, and has the same center as the celestial globe, and that any plane which passes through the center makes at its surface, that is, at the surface of the earth and of the sky, great circles, and that the angles of the planes, which angles are at the center, cut the circumferences of the circles which they intercept proportionately, it follows that in any of the distances which we measure on the earth the number of the stadia, if our measurements are correct, can be determined, but the proportion of this distance to the whole circumference of the earth can not be found, because no proportion to the whole earth can thus be derived, but from the similar circumference of the celestial globe that proportion can be derived, and the ratio of any similar part on the earth’s surface to the great circle of the earth is the same.

How, from measuring the stadia of any given distance, although not on the same meridian, we may determine the number of stadia in the circumference of the earth, and vice versa

Those geographers who lived before us sought to fix correct distance on the earth, not only that they might determine the length of the greatest circle, but also that they might determine the extent which a region occupied in one plane on one and the same meridian. After observing therefore, by means of the instrument of which I have spoken, the points which were directly over each terminus of the given distance, they calculated from the intercepted part of the circumference of the meridian, distances on the earth.

As we have said, they assume the location of the points to be in one plane, and the lines passing through the terminals of the distance, to the points which are directly overhead, must necessarily meet, and the points where they meet would be the common center of the circles. Therefore if the circle drawn through the poles were intercepted by lines drawn from the two points that were marked overhead, it would be understood that it formed the total extent of the intercepted circumference compared with the whole circuit of the earth.

If a distance of this kind is not on the circle drawn through the poles, but on another of the great circles, the same thing can be shown by observing in like manner the elevation of the pole from the extremities of the distance, and noting simultaneously the position which the same distance has on the other meridian. This we have clearly shown by an instrument which we ourselves have constructed for measuring shadows, by which instrument we can easily ascertain a great many other useful things, For on any day or night we have the elevation of the north pole, and at any hour we have the meridian position of the given distance by performing a single measurement, that is, by measuring the angle that the greatest circle drawn through the line of the distance makes with the meridian circle at the vertical point: in this way we can show the required circumference by means of this instrument, and the circumference of the equatorial circle which is intercepted between the two meridians, these meridians being parallel and circles like the equator. According to this demonstration, if we measure only one straight distance on the surface of the earth, then the number of stadia of the whole circuit of the earth can be ascertained. And as a result of this we can obtain the measurements of all distances, even when they are not exactly on the same meridian or parallel, by observing carefully the elevation of the pole, and the inclination of the distance to the meridian, and vice versa. From the ratio of the given part of the circumference to the great circle, the number of the stadia can be calculated from the known number of stadia in the circuit of the whole earth.

The opinions of Marinus relating to the earth’s latitude axe corrected by observed phenomena

First of all, Marinus places Thule as the terminus of latitude on the parallel that cuts the most northern part of the known world. And this parallel, he shows as clearly as is possible, at a distance of sixty-three degrees from the equator, of which degrees a meridian circle contains three hundred and sixty. Now the latitude he notes as measuring 31,500 stadia, since every degree, it is accepted, has 500 stadia. Next, he places the country of the Ethiopians, Agisymba by name, and the promontory of Prasum on the same parallel which terminates the most southerly land known to us, and this parallel he places below the winter solstice.

Between Thule and the southern terminus he inserts altogether about eighty-seven degrees which is 43,500 stadia, and he tries to prove the correctness of this southern termination of his by certain observations (which he thinks to be accurate) of the fixed stars and by certain journeys made both on land and on sea. Concerning this we will make a few observations.

In his observation concerning the fixed stars, in the third volume of his work, he uses these words: "The Zodiac is considered to lie entirely above the torrid zone and therefore in that zone the shadows change, and all the fixed stars rise and set. Ursa Minor begins to be entirely above the horizon from the north shore of Ocele which is 5,500 stadia distant, The parallel through Ocele is elevated eleven and two-fifths degrees.

"We learn from Hipparchus that the star in Ursa Minor which is the most southerly or which marks the end of the tail, is distant from the pole twelve and two-fifths degrees, and that in the course of the sun from the equinoctial to the summer solstice, the north pole continually rises above the horizon while the south pole is correspondingly depressed, and that on the contrary in the course of the sun from the equator to the winter solstice the south pole rises above the horizon while the north pole is depressed."

In these statements Marinus narrates only what is observed (on) the equator, or between the tropics. But what, after being learned from the records or from accurate observations of the fixed stars, are the happenings in places south of the equator, he in no wise informs us, as if one should place southern stars rather than equatorial directly overhead, or assert that mid-day shadows over the equator incline south, or show all the stars of Ursa Minor risen or set, or some of them visible at the time when the south pole is raised above the horizon.

In what he adds later he tells us of certain observations, of which, nevertheless, he is not entirely certain in his own mind.

He says that those who sail from India to Limyrica, as did Diodorus the Samian, which is related in his third book, tell us that Taurus is in a higher position in the mid-heavens than in reality it is and that the Pleiades are seen in the middle of the masts, and he continues, "those who sail from Arabis to Azania sail straight to the south, and toward the star Canopus, which there is called Hippos, that is the Horse, and which is far south. Stars are seen there which are not known to us by name, and the Dog Star rises before Procyon and Orion, and before the time when the sun turns back toward the summer solstice."

For these observations concerning the stars Marinus clearly states that some places are located more northerly than the equator, as when he says that Taurus and the Pleiades are directly over the heads of the sailors. As a matter of fact these stars are near the equator. He indeed shows some stars to be no further south than north, for Canopus can be seen by those who dwell a long distance north of the summer solstice; and several of the fixed stars, never seen by us, can be seen above the horizon in places south of us, and in places more toward the equatorial region than those in the north, as around Meroë. They can be seen as is Canopus itself, which, when appearing above the horizon is never visible to those who dwell north of us. Those who dwell toward the south call this star Hippos, that is the Horse, nor is any other star of those known to us called by that name.

Marinus infers that he himself determined by mathematical proofs that Orion is entirely visible, before the summer solstice, to those who dwell below the equatorial circle; also that with them the Dog Star rises before Procyon, which he says is observed as far south even as Syene. In these conclusions of Marinus there is nothing appropriate or of value to us because he extends the position of his inhabited countries too far south of the equator.

They are also corrected by measuring journeys on land

In computing the days one by one, occupied in journeying from Leptis Magna to Agisymba, Marinus shows that the latter locality is 24,680 stadia south of the equator. By adding together the days occupied in sailing from Ptolemais Trogloditica to Prasum he concluded that Prasum is 27,800 stadia south of the equator, and from these data he infers that the promontory of Prasum and the land of Agisymba, which, as he himself expresses it, belongs to Ethiopia (and is not the end of Ethiopia), lies on the south coast in the frigid zone opposite to ours. In a southerly direction 27,800 stadia make up fifty-five and three-fourths degrees, and this number of degrees in an opposite direction (i. e. north) marks a like temperate climate, and the region of the swamp Meotis, which the Scythians and Sarmatians inhabit.

Marinus then reduces the stated number of his stadia by half or less than half, that is to 12,000 which is about the distance of the winter solstice from the equatorial circle. The only reason for this reduction that he gives us is the deviation from a straight line of the journeys and their daily variations in length. After he has stated these reasons, it seemed to us necessary not only to show that he was mistaken, but also to reduce his figures by the required one-half.

At the outset, when writing of the journey from Garama to Ethiopia he says that Septimius Flaccus, having set out from Libya with his army, came to the land of the Ethiopians from the land of the Garamantes in the space of three months by journeying continuously southward. He says furthermore that Julius Meternus, setting out from Leptis Magna and Garama with the king of the Garamantes, who was beginning an expedition against the Ethiopians, by bearing continuously southward came within four months to Agisymba, the country of the Ethiopians where the rhinoceros is to be found.

Each of these statements, on the face of it, is incredible, first, because the Ethiopians are not so far distant from the Garamantes as to require a three months’ journey, seeing that the Garamantes are themselves for the most part Ethiopians, and have the same king; secondly, because it is ridiculous to think that a king should march through regions subject to him only in a southerly direction when the inhabitants of those regions are scattered widely east and west, and ridiculous also that he should never have made a single halt that would alter the reckoning. Wherefore we conclude that it is not unreasonable to suppose that those men either spoke in hyperbole, or else, as rustics say, "To the south," or "Toward Africa" to those who prefer to be deceived by them, rather than take the pains to ascertain the truth.

They are also corrected by measuring journeys by water

Concerning the voyage from Aromata to Rhapta, Marinus tells us that a certain Diogenes, one of those who were accustomed to sail to India, having been driven out of his course, and being off the coast of Aromata, was caught by the north wind and, after having sailed with Trogloditica on his right, came in twenty-five days to the lake from which the Nile flows, to the south of which lies the promontory of Rhaptum. He tells us also that a certain Theophilus, one of those who were accustomed to sail to Azania, driven from Rhapta by the south wind came to Aromata on the twentieth day. In neither of these cases does he tell us how many days were occupied in actual sailing, but merely states that Theophilus took twenty days, and Diogenes, who sailed along the coast of Trogloditica, took twenty-five days.

He only tells us how many days they were on the voyage, and not the exact sailing time, nor the changes of the wind in strength and direction, which must have taken place during a voyage of such long duration. Moreover he does not say that the sailing was continuously south or north, but merely says that Diogenes was carried along by the north wind while Theophilus sailed with the south wind. That the wind kept the same strength and direction during the whole voyage is related in neither case, and it is incredible that for the space of so many days in succession, it Should have done so. Therefore although Diogenes sailed from Aromata to the swamps, to the south of which lies the promontory of Rhaptum, in twenty-five days, and Theophilus from Rhapta to Aromata, a greater distance, in twenty days, and although Theophilus tells us that a single day’s sailing under favorable circumstances is calculated at 1,000 stadia (and tiffs computation Marinus himself approves) Disocorus nevertheless says that the voyage from Rhapta to the promontory of Prasum, which takes many days, as computed by Diogenes is only 5,000 stadia. The wind, he says, varies very suddenly at the equator, and squalls around the equator on either side of the line are more dangerous.

From these considerations we thought we ought not to assent to the numbering of the days, because it is plain to all that on the reckoning made by Marinus, the Ethiopians and the haunts of the rhinoceros should be moved to the cold zone of the earth, that is, opposite to ours. Reason herself asserts that all animals, and all plants likewise, have a similarity under the same kind of climate or under similar weather conditions, that is, when under the same parallels, or when situated at the same distance from either pole.

Marinus has shortened the measures of latitude around the winter solstice, but has given no sufficient reason for his contraction. Even should we admit the number of days occupied in the series of voyages that he relates, he has shortened the number of daily stadia and has reasoned contrary to his customary measure in order to reach the desired and correct parallel. He should have done exactly the opposite, for it is easy to believe the same daily distance traveled as possible, but in the even course of the journeys, or voyages or that they were wholly made in a straight line, he ought not to have believed. From them it was not possible to ascertain the distance but it was correct to assert that in latitude the places in question extended beyond the equator. Even this could be known with greater certainty from astronomical observations. Any one could have ascertained exactly the required distances if he had, with more skill in mathematics, considered what takes place in those localities. Since this observation was not made, it remains that we follow what reason dictates, that is, we must ascertain how far the distance extends beyond the equator. We can also ascertain what we require to know through information concerning the kinds, the forms, and the colors of the animals living there, from which we draw the conclusion that the parallel of the region of Agisymba is the same as that of the Ethiopians and extends from the winter solstice to the equator; although with us in places opposite to that region, that is, in the summer solstice, they do not have the color of the Ethiopians, nor is the rhinoceros and elephant to be found, yet in places not far south of us the inhabitants are moderately black such as from the same cause are the Garamantes, whom Marinus himself describes, and whom he places neither under the summer solstice nor north of it, but much too far to the south. In the regions around Meroë the inhabitants are very black, and closely resemble the Ethiopians, and there we find that elephants and other kinds of monstrous animals are bred.

Ethiopia should not be placed more to the south than the parallel which is opposite the parallel passing through Meroe

In agreement therefore with this information, viz., that the inhabitants are Ethiopians, as those who have sailed there have told us, Marinus describes the region of Agisymba and the promontory of Prasum, and the other places lying on the same parallel, as situated all on one parallel, which is opposite the parallel passing through Meroë. That would place them on a parallel distant from the equator in a southerly direction 16°25′ or about 8,200 stadia, and by the same reckoning the whole width of the habitable world amounts to 79°25′ or altogether 40,000 stadia.

Now the distance between Leptis Magna and Garama, according to Flaccus and Maternus, is placed at 5,400 stadia. The time of their second journey was twenty days, a more nearly correct time than the first because it was directly north, while the first journey of thirty days had many deviations. The travelers who several times made the voyage kept the reckoning of each day’s distance, and this was not only properly done, but done of necessity on account of the changes of the water and the weather. Just as we should have doubts with regard to distances that are great in extent, and rarely traveled, and not fully explored, so in regard to those that are not great and not rarely but frequently gone over, it seems right to give credit to the reports of the voyagers.

Explanation of the meridians and parallels used in our delineation

The meridians, according to what we have already shown, will embrace the space of twelve hours. The parallel that bounds the most southern limit of the habitable world will be distant from the equator in a southerly direction only as far as the parallel passing through Meroë is distant in a northerly direction.

It has seemed proper to us to put in the meridians at a distance from each other the third part of an equinoctial hour, that is, through five of the divisions marked on the equator. The parallels that are not of the equator we have inserted so that:

The first parallel is distant from the equator the fourth part of an hour, and is distant from it geometrically about 4°15′.

The second parallel we make distant half an hour from the equator, and geometrically distant 8°25′.

The third parallel we make distant from the equator three-fourths of an hour, and geometrically 12°30′.

The fourth parallel is distant one hour and is 16°25′. This is the parallel through Meroë.

The fifth parallel is distant one and one-fourth hours, and 20°15′.

The sixth parallel, which is under the summer solstice, is distant one and one-half hours, and 23°50′, and is drawn through Syene.

The seventh parallel is distant one and three-fourths hours, and 27°10′.

The eighth parallel is distant two hours, and 30°20′.

The ninth parallel is distant two and one-fourth hours, and 33æ20′.

The tenth parallel is distant two and one-half hours, and 36°, and is drawn through Rhodes.

The eleventh parallel is distant two and three-fourths hours, and 38°35′.

The twelfth parallel is distant three hours, and 40°55′.

The thirteenth parallel is distant three and one-fourth hours, and 43°05′.

The fourteenth parallel is distant three and one-half hours, and 45°.

The fifteenth parallel is distant four hours, and 48°30′.

The sixteenth parallel is distant four and one-half hours, and 51°30′.

The seventeenth parallel is distant five hours, and 54°.

The eighteenth parallel is distant five and one-half hours, and 56°10′.

The nineteenth parallel is distant six hours, and 58°.

The twentieth parallel is distant seven hours, and 61°.

The twenty-first parallel is distant eight hours, and 63°, and is the parallel drawn through Thule.

Besides these, one other parallel must be drawn south of the equator with the time difference of half an hour. It should pass through Rhaptum promontory and Cattigara, and should be about the same length as the parallel in the opposite part of the earth which is distant 8°25′ north of the equator.

The first of these selections is from Ptolemy, Tetrabiblos, trans. F. E. Robbins, Loeb Classical Library (London: William Heinemann, 1940), pp. 35–36. The others are from The Geography of Ptolemy, trans. Edward Luther Stevenson (New York: New York Public Library, 1932), pp. 25–28, 18–19, 29–32, 41. Reprinted by permission of the New York Public Library.


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Chicago: Claudius Ptolemy, "Ptolemy on the Field of Geography and on Divisions of the Earth," A Source Book in Geography, trans. Edward Luther Stevenson in A Source Book in Geography, ed. George Kish (Cambridge: Harvard University Press, 1978), 105–116. Original Sources, accessed July 2, 2022, http://originalsources.com/Document.aspx?DocID=5T6ZZS1IUA4LJG2.

MLA: Ptolemy, Claudius. "Ptolemy on the Field of Geography and on Divisions of the Earth." A Source Book in Geography, translted by Edward Luther Stevenson, in A Source Book in Geography, edited by George Kish, Cambridge, Harvard University Press, 1978, pp. 105–116. Original Sources. 2 Jul. 2022. http://originalsources.com/Document.aspx?DocID=5T6ZZS1IUA4LJG2.

Harvard: Ptolemy, C, 'Ptolemy on the Field of Geography and on Divisions of the Earth' in A Source Book in Geography, trans. . cited in 1978, A Source Book in Geography, ed. , Harvard University Press, Cambridge, pp.105–116. Original Sources, retrieved 2 July 2022, from http://originalsources.com/Document.aspx?DocID=5T6ZZS1IUA4LJG2.