APPENDICES
[[389]]
APPENDIX A
Notes on the Geography and Meteorology of Mashonaland
By Robert M. W. Swan, Esq.
Central Mashonaland consists of elevated granite plateaux, varying in height between 3,000 and 5,000 feet. Through the surface of these plains rise groups of isolated little granite hills which are most remarkable and varied in form, and which sometimes attain an elevation of 1,000 feet above their base, but more frequently they are about 400 feet high. Generally they are composed of enormous broken blocks of granite, but often they are dome-shaped and of one unbroken mass of rock, and suggest the idea of huge bubbles on the surface of a molten mass. The summits of the latter kind of hills are, of course, quite inaccessible. They are not hills left in relief by the denudation of the surrounding country, but, judging from exposed sections of some that I have seen, they have been elevated by a force acting at a comparatively small distance below the present surface, and they are older than the stratified rocks of the country.
On the granite plateaux one meets with patches of stratified rock—of quartzites and schists, and rarely some crystalline limestone. Magnesia, too, is sometimes present, [[390]]notably at Umtali, and in the steatite which occurs near the Great Zimbabwe, of which many of the objects found in the excavations were made. The strike of the strata is generally east and west, and the various patches arrange themselves in several fairly continuous lines running across the country in the same direction as the strike. These semi-continuous deposits or belts of stratified rock are generally two or three miles wide, and in them occur the gold-bearing quartz reefs. The most southerly belt that I know of in Mashonaland proper passes by Fort Victoria, and probably crosses the Sabi River about latitude 20°. The next large one passes by Umtali and the ’Mfuli River, where it crosses the waggon-road, and so on to Hartley Hill. This belt includes Mount Wedsa, the highest mountain in Mashonaland. Next in order comes the Mazoe deposit, which perhaps also includes the Kaiser Wilhelm gold-field. These deposits are all fairly similar in nature, but no fossils have been found in them, and their age has not been determined. They probably represent a continuous sheet of stratified rock, all of which has been denuded away except the above-mentioned belts. They generally present a rugged surface, elevated in mountain ranges, which often rise 1,500 and 2,000 feet above their base, and, although they are nearly always steep, they are rarely precipitous. These mountains are regular and beautiful in outline, and refresh the eye after it has grown wearied of the grotesque forms of the granite hills. The soil on the stratified rocks is more fertile than it is on the granite, and the vegetation is more charming; the very coarse grasses of the granite soils being replaced by many flowering plants.
The ruins which have just been described are all built on granite, but are generally within a short distance of the quartz formation; and the ruins at Zimbabwe are situated four miles from the southern edge of the quartz belt. At Zimbabwe we found little clay crucibles in which gold had been melted, [[391]]and an accumulation of quartzite rock which had been obtained from the casing of a quartz reef. I carefully tested this rock for gold, but could only find a very minute trace; so I conclude that it had been rejected as too poor for treatment. While at Zimbabwe, whenever I could spare time from the excavations, I made excursions to the quartz belt, and searched for old workings and gold reefs. I found one reef carrying a small quantity of gold, but no old workings. Since then, however, rich gold reefs have been discovered about twenty miles to the north-west of Zimbabwe, and from these probably the ancients obtained their quartz. The quartz formation near the little ruin at the Mazoe River has been much worked for gold, and the Manica belt seems to have been even more exploited. Where the high plateau breaks down at Massi-Kessi an enormous amount of alluvial has been worked. The old people must have obtained, from both the alluvial and the reefs, a great quantity of gold to repay them for the work that they did, and there is no reason to suppose that they have exhausted the reefs; indeed, I have seen at the bottom of old workings the reef continuing and carrying visible gold.
Besides gold reefs, these quartz belts contain much iron ore and some manganese. In two isolated patches of the quartzite formation at the Doroba Mountains, near the Sabi River, I found great masses of rich magnetite and hematite, and on the top of Mount ’Nyaguzwe, near Fort Victoria, there is also a mass of magnetite; in fact, so very abundant is iron ore, that compass bearings can rarely be taken with safety from hills in the quartz formation. Along the right bank of the Sabi River, near Mount Wedsa, are many native villages, whose one industry is iron smelting. They obtain the ore from Mount Wedsa, which is renowned far and wide in Kaffirland as an iron-producing mountain. The mineral they select is not very rich, and is consequently more easily [[392]]smelted, and it contains some manganese. The iron they produce is very pure, and is consequently soft and easily fashioned into weapons and tools. Their anvils are simple blocks of hard diorite, on which they hammer with another smaller block.
The tributaries of the Sabi River flowing near Zimbabwe have been ill-defined on previous maps. The ’Mpopotekwe joins the ’Mtelekwe and the ’Mshagashe flows into the united stream a short distance south of Zimbabwe. This river, under the name of the ’Mtelekwe, then flows into the Lunde, and not to the Sabi direct. The Tokwe joins the Lunde farther north. The most interesting geographical work that we did was on our expedition to the Sabi River, and on that from Fort Salisbury to ’Mtoko’s, and down by Mangwendi’s and Makoni’s country to Umtali. On our journey to the Sabi we crossed a great many of its western tributaries; and as the same streams rose near the waggon-road, and we crossed them pretty far down their courses, we were able to lay down their direction for a considerable distance with certainty. The Sabi River itself, in latitude 19° 15′, we found was placed twenty miles too far west in former maps; and from the information which I gathered from the natives, in the latitude of Zimbabwe, it must be about fifty miles farther east than it is placed in these maps. This river, where we struck it, was a considerable stream flowing rapidly over a rocky bed. It had fallen about 1,800 feet from its source near Fort Charter, and had 2,700 feet more to fall before it reached the sea. When it has received all the tributaries we crossed it must be a very big river.
Going from Fort Salisbury to ’Mtoko’s we crossed many tributaries of the Mazoe River, which were either not shown at all in former maps, or were most inaccurately placed. We recrossed these streams again farther up returning from ’Mtoko’s to Mangwendi’s. I also got excellent views of them [[393]]from the various mountains which I ascended, so that I was able to lay them down in my map with certainty. To the eastward of ’Mtoko’s we could see the high veldt breaking into mountain ranges as it descended towards Gouveia’s country.
Approaching Mangwendi’s, and also going between Mangwendi’s and Chipunza’s, our way lay along a very high watershed, on the western side of which rose some of the eastern tributaries of the Sabi River, the most important of which was the ’Msheke. At Makoni’s we reached the highest part of the plateau, and this is, with the exception of some villages on Mount Yenya, the highest inhabited part of Mashonaland. From Makoni’s to Mount Yenya the country is broken; and the descent is very rapid, but on the east of our route the descent is still more rapid and the mountains more imposing. On the north side of Mount Yenya flows the Odzi River, which is there a very considerable stream. Mount Yenya is a most imposing mountain and the highest in Mashonaland, with the exception of Mount Wedsa. It rises to a height of 5,800 feet above sea level, and within 300 feet of its summit are several villages which own a considerable number of cattle. It probably represents the Mount Doe which the Portuguese place on their maps about this part, and which they say is 7,900 feet high, for certainly there is no mountain near Mount Yenya of equal height. Between Umtali and Massi-Kessi the country is extremely mountainous, and the scenery is the grandest that we saw in Mashonaland. We lost 1,400 feet in height between these two places. A short distance after leaving Massi-Kessi we crossed the Revwe River, and our way lay along a watershed about 2,000 feet high. This watershed is thickly wooded, and is traversed sometimes by deep ravines. On the left hand the streams flow to the Pungwe River, and on the right to the Revwe and the Muda and Mutuchiri Rivers. [[394]]Approaching Sarmento, the country falls rapidly to nearly sea level; and thence to the coast we traversed a flat alluvial country through which the Pungwe River sluggishly flows. This swampy level country swarms with game, especially towards the end of the dry season, but the vegetation is not nearly so luxuriant as one would expect, and some parts of this country are quite bare.
I have been careful throughout to spell the native names in accordance with the rules laid down by the Royal Geographical Society. The sound of the Bushman clicks which occurs so often in the names of places and in the names of tribes derived from the names of places, but most frequently of all in the names of rivers, is slurred over by the present tribes, and represented by a combination of letters. As I know of no rule for the spelling of these sounds, I have represented them by an inverted comma and the consonant nearest in sound. In maps of Africa north of the Zambesi these clicks are generally spelt in this way, although the comma has often dropped out, as in words like ‘Nyanza,’ ‘Mpwapwa,’ ‘Mvumi;’ but south of that river cartographers have been less accurate, and have often used various vowels instead of the comma. I have used such mis-spellings of the native names only when they have been long established and passed into constant use: as ‘Umtali’ and ‘Inhambane.’
A point of interest in the remote history of the country and of the ruins which we examined—for the old people doubtless entered the country by this coast—is the growth of the land at the mouth of the Pungwe River and around Sofala. From about Sarmento down to Beira one passes over a low alluvial country which has been slowly encroaching on the sea for ages. I am sorry that in the rush to the coast I did not have time to collect data to enable me to form any idea of the quantity of mud deposited from the waters of the Pungwe in a given time, but its waters hold in suspension a [[395]]great quantity of fine clay derived from the decomposition of the granite in its basin, and this is deposited where the river enters the sea. The distance from Sarmento to Beira as the crow flies is sixty-five miles, so that at some period the road to the interior must have been shortened by this amount, and even in early historical times some part of the journey across the low fever belt would have been saved. The site of ancient seaports will now be far inland, so it need not surprise us that remains of these ports have not yet been found.
Owing to frequent absence from camp, I was unable to read the thermometer and barometer as continuously and regularly as I could have wished, but the readings which I did take give us some idea of what the climate at Zimbabwe was in June and July last year. We arrived there on June 6, after a week of south-east winds, high barometer, and rain and mist. The wind then gradually fell and the barometer with it, and we had three weeks of fine calm weather. The barometer reached its minimum on June 27, and at the same time the difference of the readings of the wet and dry bulb thermometers was at its maximum. The air was then very dry and the sky clear, with light north winds which were evidently local in origin, and the temperature at night fell below freezing-point, so that in the morning we saw a light deposit of hoar-frost. Immediately after this the barometer began to rise, there were light south-east winds, the atmosphere became moister, and on July 4 the south-east wind had increased considerably in strength, and some rain fell. From this time until the end of our stay at Zimbabwe, on August 2, the barometer slowly rose and fell, its range being limited to about three-tenths of an inch; and whenever the south-east winds blew at all strongly the barometer rose and we had mist and rain. We had during this period generally about a half-day of rain each week. [[396]]
At first sight it seems surprising that we should have windy wet weather with a high barometer, but we must remember that the only winds which can bring rain to Zimbabwe, at least in winter, are the south-easterly winds, and these, like all other winds blowing towards the equator, increase the atmospheric pressure. Zimbabwe is situated on the edge of a plateau about 3,400 feet above sea level. The country breaks down gradually towards the south and east and more rapidly towards the west, while towards the north it rises gently until after about 100 miles it attains an altitude of nearly 5,000 feet. The west winds, if they do blow, have to traverse the continent and the high country about the sources of the Limpopo before they reach Zimbabwe, so that they will deposit their excess of moisture for the altitude of Zimbabwe before reaching that place; and the northerly winds will tend to increase in temperature, and consequently in dryness, after falling from the high country towards the north; so that westerly and northerly winds will not part with moisture at Zimbabwe. The predominant winds in this latitude are the south-east trades, and they, carrying their moisture from the Indian Ocean, are forced to rise as they pass over this country, and they consequently expand and are lowered in temperature and so deposit much of their moisture on this edge of the high plateau. A similar winter climate seems to prevail in most parts of Mashonaland, the edges of the plateaux receiving most of the moisture. Manica is situated much nearer the sea than Zimbabwe, and the country there falls much more rapidly towards the east (it falls 1,400 feet in ten miles near Umtali), and consequently the rainfall there is heavier. Fort Salisbury is better situated for a dry winter, for it is in the middle of a high plateau, and the south-east winds will have parted with most of their surplus moisture for that altitude before they reach it. The driest time of the year in Mashonaland is from August to November. I may [[397]]mention that the greatest difference I observed in the readings of the wet and dry bulb thermometers was 24° F. at the ’Mshabetsi River, at an altitude of 2,140 feet, on May 13 at 2 P.M.; the readings being 64° and 88° respectively. At Zimbabwe during June and July the difference in readings varied from 0° to 20° F., and the dew point sometimes fell to 32° F. at midday. The extreme range of shade temperature in the two months was 46° F. [[398]]
APPENDIX B
List of Stations in Mashonaland Astronomically Observed, with Altitudes
By Robert M. W. Swan, Esq.
| Stations | Latitude | Longitude | Heights[1] | ||||
| ° | ′ | ″ | ° | ′ | ″ | feet | |
| Mafeking | 25 | 51 | 1 | 25 | 41 | 0 | — |
| Ramatlabama River | 25 | 37 | 57 | — | — | ||
| At Pan | 25 | 30 | 13 | 25 | 8 | 15 | — |
| Kanya, 11 miles S.S.E of | 25 | 7 | 2 | 25 | 8 | 15 | 3580 |
| Kanya | 24 | 58 | 30 | 25 | 16 | 0 | 3750 |
| Molopolole | 24 | 25 | 30 | 25 | 21 | 0 | 4020 |
| Molopolole, 4 miles N. of | 24 | 21 | 30 | 25 | 21 | 30 | 3872 |
| Klippan, ½ mile N. of | 24 | 17 | 12 | — | 4020 | ||
| Kurumurwa | 24 | 8 | 33 | — | 3570 | ||
| Khemi | 23 | 50 | 8 | — | 3490 | ||
| Boatlenama, 15 miles S.E. of | 23 | 42 | 20 | 25 | 35 | 30 | 3540 |
| Boatlenama | 23 | 32 | 30 | — | 3400 | ||
| S. of Selinia Pan | 23 | 27 | 11 | — | 3120 | ||
| N. of Selinia Pan | 23 | 20 | 51 | 26 | 3 | 15 | 3050 |
| Near Hataloklu Vley | 23 | 15 | 4 | 26 | 10 | 53 | 3140 |
| S. of Shoshong | 23 | 8 | 47 | 26 | 19 | 30 | 3160 |
| Near Shoshong | 23 | 4 | 0 | 26 | 28 | 0 | 3310 |
| At stream | 23 | 1 | 57 | 26 | 41 | 30 | 3260 |
| Near Mahalapsi River | 22 | 57 | 41 | 26 | 51 | 15 | 3240 |
| Chuloan Vley | 22 | 46 | 0 | 27 | 6 | 30 | 3010 |
| Palapwe | 22 | 37 | 30 | 27 | 18 | 0 | 3150 |
| At Lotsani River | 22 | 32 | 45 | 27 | 21 | 30 | 2740 |
| At Lotsani River | 22 | 33 | 58 | 27 | 34 | 0 | 2480 |
| At Lotsani River | 22 | 32 | 37 | 27 | 46 | 45 | 2450 |
| Near Elibi Fort | 22 | 32 | 55 | — | 2300 | ||
| Near Elibi Fort | — | — | 2230 | ||||
| At Muralla Vley | 22 | 32 | 55 | 28 | 10 | 30 | 2290 |
| Makwenje River | 22 | 26 | 56 | 28 | 21 | 30 | 2275 |
| Pakwe River | 22 | 15 | 20 | 28 | 24 | 15 | 2400[[399]] |
| Marapong River | 22 | 7 | 38 | 28 | 31 | 0 | 2230 |
| Matlaputla River | 22 | 3 | 39 | — | — | ||
| Maklutsi Camp | 22 | 0 | 42 | 28 | 38 | 15 | 2010 |
| Maklutsi River | 21 | 58 | 20 | 28 | 41 | 0 | 1870 |
| Metsimachokwan River | 21 | 49 | 55 | 28 | 52 | 0 | 1920 |
| Semalali | 21 | 53 | 2 | 29 | 0 | 40 | 2080 |
| Baobab Spruit | 21 | 53 | 17 | 29 | 14 | 0 | — |
| Fort Tuli | 21 | 55 | 20 | 29 | 20 | 15 | — |
| Ipagi River | 21 | 51 | 59 | 29 | 36 | 15 | — |
| Sigabi River | 21 | 43 | 53 | 29 | 42 | 30 | — |
| ’Msingwan River | 21 | 39 | 7 | 29 | 48 | 15 | 1720 |
| ’Mshabetsi River | 21 | 26 | 22 | 29 | 57 | 15 | 2140 |
| Mount Yanda | 21 | 21 | 57 | 30 | 6 | 15 | 2330 |
| Bubye River | 21 | 20 | 30 | 30 | 14 | 0 | 2090 |
| ’Nyamanda | 21 | 11 | 34 | 30 | 23 | 15 | — |
| Mount Host | 21 | 9 | 10 | 30 | 30 | 20 | 2250 |
| Near Nwanetsi River | 21 | 5 | 16 | 30 | 38 | 30 | 1910 |
| Near Nwanesti River | 20 | 59 | 23 | 30 | 41 | 0 | 1880 |
| Near Mount Ibonda | 20 | 49 | 49 | 30 | 42 | 0 | 2130 |
| Lunde River | 20 | 41 | 6 | 30 | 44 | 45 | 1970 |
| Near Naka Mountains | 20 | 35 | 54 | 30 | 45 | 0 | 2130 |
| ’Mlala | 20 | 27 | 9 | 30 | 47 | 30 | 2580 |
| Tokwe River | 20 | 23 | 5 | 30 | 53 | 30 | 2380 |
| Providential Pass | 20 | 11 | 11 | 30 | 57 | 45 | 3090 |
| Fort Victoria | 20 | 7 | 53 | 31 | 0 | 0 | 3380 |
| Zimbabwe | 20 | 16 | 30 | 31 | 7 | 30 | 3340 |
| ’Mshagashe River | 20 | 3 | 40 | — | 3200 | ||
| Makori | 19 | 38 | 29 | 30 | 58 | 30 | 4200 |
| Chekatu | 19 | 38 | 49 | 31 | 3 | 0 | 4100 |
| Gona | 19 | 36 | 52 | — | 4350 | ||
| ’Msingana | 19 | 31 | 30 | — | 3650 | ||
| Kutimasinga’s | 19 | 38 | 19 | 31 | 37 | 0 | 3250 |
| Lutile | 19 | 34 | 12 | — | 3600 | ||
| Matindela | 19 | 30 | 23 | 31 | 51 | 45 | 3350 |
| Near Mount Wizinde | 19 | 17 | 0 | — | 3250 | ||
| Near Mwairari River | 19 | 14 | 56 | 32 | 2 | 45 | 2900 |
| Mukubu River | 19 | 8 | 45 | 32 | 4 | 15 | 2700 |
| Sabi River | 19 | 7 | 40 | 32 | 1 | 30 | 2900 |
| Ampsäi River | 19 | 6 | 41 | — | 2950 | ||
| Zamopera | 19 | 0 | 17 | 31 | 39 | 15 | 3660 |
| Mafusaire’s | 18 | 56 | 26 | — | 3950 | ||
| East of Smet’s Kraal | 18 | 51 | 25 | — | — | ||
| West of Kwende’s Kraal | 18 | 48 | 25 | 31 | 25 | 45 | 4220[[400]] |
| ’Mtigesa’s | 18 | 48 | 30 | 31 | 16 | 45 | 4570 |
| Fort Charter | 18 | 35 | 40 | 31 | 9 | 45 | 4408 |
| ’Mfuli River | 18 | 18 | 35 | 31 | 5 | 30 | 4080 |
| Near stream | 18 | 10 | 15 | 31 | 10 | 15 | — |
| S. of Hanyani River | 18 | 0 | 22 | 31 | 3 | 15 | 4800 |
| Fort Salisbury | 17 | 49 | 30 | 31 | 4 | 15 | 4820 |
| Fleming’s Camp, Mazoe River | 17 | 32 | 48 | 30 | 56 | 0 | — |
| Yellow Jacket Mine, ditto | 17 | 28 | 32 | 31 | 4 | 15 | 4030 |
| Madelaywa’s | 17 | 48 | 30 | 31 | 12 | 0 | — |
| Musungaikwa’s | 17 | 52 | 33 | 31 | 20 | 15 | 5010 |
| Nora River | 17 | 55 | 13 | 31 | 29 | 0 | 4470 |
| Kunzi’s | 17 | 53 | 40 | 31 | 33 | 0 | 4400 |
| Yandoro’s | 17 | 47 | 0 | 31 | 41 | 45 | 4720 |
| Bambabashla’s | 17 | 40 | 30 | 31 | 48 | 0 | 4410 |
| Mahume River | 17 | 31 | 0 | 31 | 57 | 45 | 3420 |
| Near Lutsa | 17 | 23 | 30 | 32 | 9 | 0 | 3450 |
| Near ’Mtoko’s | 17 | 23 | 50 | 32 | 14 | 0 | 3900 |
| ’Nyandea River | 17 | 32 | 5 | 32 | 8 | 30 | 3600 |
| Nyamashupa River | 17 | 39 | 22 | 32 | 2 | 15 | 3900 |
| Near Mount Masunsgwai | 17 | 50 | 12 | 31 | 54 | 15 | 4350 |
| Yaungurukwe River | 17 | 59 | 25 | 31 | 45 | 45 | 4700 |
| Mangwendi’s P.S. | 18 | 6 | 42 | 31 | 39 | 30 | 4870 |
| Nyanger Mountain | 18 | 15 | 20 | 31 | 46 | 0 | 4850 |
| Chikamondi River | 18 | 21 | 6 | 31 | 56 | 30 | 4810 |
| Mount Ruanda | 18 | 22 | 30 | 32 | 7 | 30 | 4830 |
| Chipunza’s | 18 | 27 | 30 | 32 | 10 | 15 | 4450 |
| Near Chigono’s | 18 | 33 | 50 | 32 | 17 | 0 | 4450 |
| Near Yenya Mountains | 18 | 45 | 0 | 32 | 22 | 45 | 3620 |
| Odzi River drift | 18 | 48 | 50 | — | 3420 | ||
| ’Mtasa’s | 18 | 44 | 30 | 32 | 29 | 0 | 4170 |
| Umtali, our camp | 18 | 53 | 30 | 32 | 32 | 45 | 3600 |
| Massi-Kessi (Portuguese camp) | 18 | 53 | 45 | 32 | 44 | 30 | 2200 |
| Mineni River | 18 | 56 | 0 | 32 | 50 | 30 | 2140 |
| Lusika River | 18 | 59 | 27 | 33 | 2 | 0 | 2000 |
| Vundusi River trib. | 18 | 59 | 10 | 33 | 13 | 0 | 2000 |
| Near Chimoia’s | 18 | 59 | 0 | 33 | 20 | 0 | 2140 |
| Zombana River | 18 | 57 | 15 | — | 1930 | ||
| Makumbese River | 19 | 2 | 10 | — | 120 | ||
| Vley | 19 | 8 | 35 | — | 100 | ||
| Mutuchiri River | 19 | 16 | 40 | — | 50 | ||
| ’Mpanda’s | 19 | 23 | 30 | 34 | 32 | 30 | 20 |
[[401]]
[1] The heights have been obtained with aneroid and boiling-point thermometers, and with the exception of that of Zimbabwe, where we stayed some time, are only approximate. [↑]
APPENDIX C
Addenda to Chapter V
By R. M. W. Swan, Esq.
Since writing the preceding pages ([Chapter V].) it has been found to be possible from the measurements made at Zimbabwe to determine the radius of another curve of the outer wall of the great temple. This part of the wall extends from B in a north-westerly direction for 111 feet, to a point which we shall call C. The radius of its curve is 133 feet, so that the diameter of the circle of which it is a part is equal to one half of 17·17 × 3·143, and the centre of the curve (which we shall call W) is situated on the meridian line from the altar through the main doorway. The middle point of this arc B C, the S.S.E. doorway of the arc G, the centres G and W, all lie in one and the same straight line. This line cuts the meridian at an angle of 30°, and when produced will pass over the outer wall at a point which is marked by a step which is built across the top of the wall. A line drawn in a similar way from the middle of the arc K B through the centre of the great tower, the altar, and P, also cuts the meridian at an angle of 30°, but from its other side. As the original wall no longer exists at the point where this line would pass we cannot say if its position was marked on the wall.
These lines of sight seem to have been used, like the meridian lines, for the observation of stars, but of stars off the [[402]]meridian. It could hardly have served any useful purpose to observe several stars crossing these lines unless they all had the same polar distance; for stars with different polar distances would cross the lines at different lengths of time before and after their culminations. Nor, in the latitude of Zimbabwe, would any individual star cross the lines at any important time in its daily circuit. But if we suppose that this temple is built on the model of one in the parent country in the northern hemisphere, it is easy to imagine a useful purpose which these lines may have served. In the latitude of Southern Arabia, for instance, an observer facing north would see the North Pole elevated about 15° above the horizon. If we compare the northern portion of the sky to a watch dial, the stars will represent the moving hands, the pole the centre of the dial, the meridian the XII. and VI. hour-points, and the III. and IX. hours will be marked by a horizontal line passing through the pole east and west. When stars cross this line they may be said to be at their east or west elongation. Now it seems probable that the two lines in question would be used in the parent country to observe a star having a north polar distance of 30° when it was at its east and west elongations and six hours from the meridian.
We have before remarked that none of our trigonometrical functions seem to have been recognised by the builders of Zimbabwe, and that the angular values of the arcs are of no special importance when measured in our way. But they must have been of importance to the builders of the temples. The locating of the centres of the arcs on the several meridian lines, supposing the meridian lines were first laid down in planning the temples (as the central one undoubtedly was in the great temple), does not really determine the intersecting points of the arcs; for, were the centre moved along the meridian lines in either direction, the points of intersection would change their positions and the lengths of the arcs would be altered. [[403]]
The lengths of the arcs seem to have been determined by the intersections of circles of radii different from those of the arcs themselves, but the lengths of whose radii were determined by the same system as those of the arcs. The centres of the intersecting circles are situated on the radius of the arc which lies midway between its extremities, and the distance between the arc and the intersecting circle measured on the same radius produced is equal to the diameter of one of the towers.
The arc AK is built on a curve of 107·8 feet radius; and if a circle be drawn as described with a radius of 169·3 feet, it will determine the length of the chord of the arc at 107 feet, and the distance between the two arcs measured on the middle radius will be 5·45, which is equal to the diameter of the little tower.
The arc KB treated in the same way, with a curve of 84·6 feet, and with a distance of 17·17 feet (the diameter of the great tower) between the intersecting circle and the arc, has the length of its chord fixed at 129½ feet. These two lengths of 107 and 129½ feet agree to within six inches with our actual measurement of the wall itself.
If we apply our system to the arc BC in an exactly similar manner, but with the distance between the circle and the arc made equal to the radius of the great tower, we find that the length of its chord should be 111 feet; and this also agrees closely with our measurements.
The arc of the eastern temple on the hill has a radius of 42·3 feet, and if a circle of 169·3 feet be applied to it with a distance of 17·17 feet between the circle and the arc, we find that the length of its chord should be 72 feet; and this is exactly what we make it on our plan. This also explains the hitherto inexplicable position of the eastern doorway.
In a similar way we determine the length of the chord of the great wall in the western temple to be 140 feet; but as the [[404]]ends of this wall are in a ruinous condition, and as the present outer face is not of the original period, we cannot say whether this was the actual measurement or not.
With two exceptions, there are no other arcs which are sufficiently complete to allow us to ascertain their original measurements. These exceptions are the arc in the little temple at G, and that from the doorway to A. In the former case, the length of the arc is fixed by the two doorways; and as one of these is placed north of the centre in order to permit of observation along the meridian line, and the other is made to serve the same purpose for the line GW, it is obvious why the length of this arc was not determined in the same way. In the latter case, as one end of the arc is at a northern doorway, and as we are not quite certain of the length of the radius of the arc itself, we have not attempted to determine the length of its chord.
It is much to be desired that more of the plan of the original temple should be recovered, and this can only be done by careful excavation conducted by some one of experience in the art; for an inexperienced or careless workman could easily and unwittingly remove any of the remaining mortarless foundations without ever discovering that he had done so. [[405]]