The district forms an excellent sphere of usefulness: and it is occupied by the Norwegian brethren in force. They have established nine principal stations, occupied by seven missionaries. The people have been somewhat prejudiced against these brethren, as not being Englishmen and of the same Society as those who first instructed them. But they are overcoming these prejudices; and Mr. Eng assured us that there is decided improvement in their congregations and schools. We could not wish it otherwise. Trained in the Evangelical school of the Norwegian Church, these brethren are anxious to work in harmony with the Friends and ourselves: questions of jurisdiction have practically been settled between us. And we can truly wish them God speed in their labours. Their reception of Mr. Sewell, my colleague and myself at all these stations was affectionate and cordial in the extreme.
At Betafo we were in the neighbourhood of the volcanoes once more: and having expressed our desire to examine them carefully, Mr. Eng kindly offered to accompany us. Ivoko, the noblest of all the craters in this district, was only two miles from the house. We had seen it from far down the valley, towering above the country; and we were anxious to climb to the summit, in the hope that by its means we might connect the eastern and western lines of our survey: as well as obtain a good view of the district at large. In this plan we found complete success. But our friends had resolved that we should have ample comfort in our day’s work. Abundant provision was made for our wants: the children of the family were delighted to join us: and a large number of the Christians of Betafo, anxious to show us respect, also accompanied us. Our visit to the Ivoko crater turned out a pleasant jaunt rather than a day of toil: and under a bright sky, with little wind, it yielded us thorough enjoyment.
We had a good climb: the total ascent being eleven hundred and thirty feet. Our native friends, used to hills, coolly walked right up the steep side, and thought nothing of it. Others of us took the more gentle ascent or were carried by our men, who enjoyed the holiday, as much as ourselves. The prospect from the summit was truly beautiful. Ivoko, we saw, was a vast crater, a quarter of a mile across; the encircling wall was complete, except at the south where the opening was fifty feet wide. The western wall is higher than the eastern. Beneath us, half a mile to the east, was another crater, Iatsífitra, second only to Ivoko, with its opening to the north. Long narrow mounds of volcanic rocks, running out from each of these hills showed the course taken by the molten lava streams. Both hills were covered inside and out with living grass. On the north-west shoulder of Ivoko were two other large craters, overhanging Betafo: two more were close by at the north-east: and others were conspicuous ten miles to the north. On the south again were several others, the horse-shoe shape being very marked in all. While ten miles to the south, was the round crater of Tritriva, with a green lake, deep down within. Far away to the east were other craters near and to the north of Sirabe.
Our survey of the country had now been carried along the western districts of Imerina, and thence to the south; and it had embraced the whole country lying between the Ankárat mountains and the great ridges and peaks of Ménabé. On our former journey we had laid down the inner portions of the Vákin Ankárat; Mr. Cameron had determined the latitude of Betafo, Sirabe and Votovorona, nearly in a line; and we had examined the whole eastern side of the upper plateau from the capital to the south border of the Betsileo. At Ivoko we stood midway between these separate lines of observations: a large number of the principal peaks and positions were in sight; and we enjoyed an excellent opportunity of comparing them together, and testing the accuracy of our own work. When duly worked out, it was satisfactory to find that the sets of observations were consistent with one another, and that the discrepancies were few and within small compass. It is from these observations that our Maps have been constructed.
Descending to the crater of Iatsifitra, of which I obtained a photograph, we observed that the lava rocks, which had issued from it to the north, were black, sharp and fresh, as if they had been broken yesterday. On its eastern side was a plain, a mile square, covered with heaps of broken lava, like stone cottages, fortresses, and ruined palaces. I counted thirty greater piles: and noted numberless smaller ones. It was clear that, like the Phlegrœan fields in Italy and the neighbourhood of Mouna Roa in Hawaii, the entire plain had at some time been on fire; and that a hundred jets of fire and flame and molten lava had spurted from its surface, hurling their blazing rockets into the sky. The heaps were now old and moss-grown: but one of the peasantry informed Mr. Sewell, that there was a kind of tradition amongst the people, that their ancestors had seen these flames bursting forth. They called the fire áfo-to: and the lava kitroka.
Near to Betafo in a cutting, ten feet deep made by a stream, I observed a specimen of the strata formed by the successive eruptions of these volcanoes. At the bottom were lumps of lava, somewhat small. Above these came several bands of brown earth: then one of black earth: above this several strata of ashes, and of lava gravel: above these again were strata of earth. Similar strata we had seen in a cutting in the Mándridráno: and subsequently saw others under the hill of Ivohitra in Sirabe.
I need not give the details of our inquiries and their results on each day of our journey. Travelling farther east, across Sirabe and round the southern end of Ankaratra we had the lava still, with long tongues, cinder heaps, and old craters again and again. We ascended one of the noblest hills in the country, the conical peak of Votovorona, a most important station in our survey: and we found it to be volcanic. Another fine cone to the east of it, Ihankian, was volcanic also. In this district we found sixty of these cones and craters. Altogether in this important journey we saw and counted a hundred extinct craters, extending over an arc of ninety miles, not reckoning the central mass of Ankárat, the finest of all, round one side of which this great arc bends. Even these do not exhaust the tale. The volcanic belt appears once more to the northward in the lofty hills with which the island terminates. The peak of Mataola is volcanic. Mount Amber is volcanic: the renowned fortress close to it is an ancient crater. Nosibe is an island full of volcanoes. Mayotta and Johanna in the Comóro isles are full of craters, lava peaks and lava streams. What a mighty volcanic force must have been exerted over this enormous area! Does Java itself show a more wonderful volcanic field? If human eyes could have beheld and appreciated them, what a scene of indescribable grandeur must have been presented when these volcanoes were active: when the land was rocked with earthquakes, and the mighty hills of gneiss and granite were upturned and rent in pieces: when showers of blazing rocks shot out like meteors into the lurid night, and the molten lava streams flowed like red rivers out of the mouths of these flaming furnaces. Wonderful in the history of the earth has been the agency of fire: nowhere can that agency have been exhibited more grandly in the present age of the earth’s formation than on the great volcanic field of Madagascar.
Among the adjuncts of the volcanic field we found four hot springs, three of which are near together in Betafo and Sirabe. The temperature of the spring at Betafo, as tried by Mr. Cameron on our first visit was 130° Fahr. The water seemed perfectly tasteless.
In three places we also found jets of carbonic acid gas. Beneath the broad and level plain of Sirabe, extending over fifty square miles, there is evidently a great deposit of lime. The pits of Sirabe, worked by the government convicts, supply nearly all the lime used for building both in the Capital and Imerina at large. With the exception of some lime deposits, containing satin spar, north of Ankárat; and a little sandstone in South Betsileo, this lime of Sirabe is the only secondary rock we met with or heard of in the upper districts of Madagascar. It is massive lime and contains no fossils. It is from this lime that the wells of carbonic acid gas are derived. One well with numerous jets was connected with a filthy mud pool; the water bubbled all over the surface and our bearers could not imagine why it remained quite cold. In a second case the tubular well was dry, and we found butterflies and various insects dead and dying around its mouth: we were told that frogs and mice are also at times found dead there. Among the lime pits the bubbling springs were numerous. At one point a huge tufa rock has been formed, having caverns with stalactites on its eastern side. On the top of the rock there is a natural basin: the water of a spring continually flows up through a crevice, bubbling as it rises. And thus it provides neither more nor less than natural soda water, of which we could drink, as we liked, without charge.
During our journey we looked everywhere for columnar basalt: but failed to find it. We saw abundance of lava, great and small, and of volcanic earth: but of columnar rock there seemed to be none. At last we found a single patch of it, about fifteen miles north of Voto Vorona. It covered a space of thirty feet by twenty: the columns were, as usual, six-sided: and the pillars exposed on the edge of a low ridge were four feet long. It is in the neighbourhood of these volcanoes that all the metals and peculiar earths in the island are said to be found. A district south-east of Sirabe and near to the Mania, is said to possess copper. Sulphur in small quantities is found at the south end of Ankárat. The lime is in Sirabe and a little of it north of Ankárat. Iron is found in abundance in the hills of Amoronkay, fourteen miles from the Capital and to the east of Ankárat. It is also abundant in the lofty mountain of Ambóhimiangára on the north-east corner of Lake Itasy. On the whole the native metallic supply in Madagascar seems poor and scanty.