Rock Ledges Research Articles

Contemporary Cartography: Division of National Mapping, Department of National Development

The map described and illustrated in this issue, is portion of 1:250,000 sheet, Barrolka SG54-11, R502 Series. The terrain in this area consists of sandridges, low eroded rock ledges and outcrops, surrounded by large areas of country subject to inundation in wet seasons. The purpose of this article is to outline the compilation and fair drawing stages of the map production process and to present in more detail a description of the hill-shading technique as used by the Division for this map series.

Adaptation to Habitat in a Group of Annual Plants

Clapham (1946) has emphasized that the persistence of a species at a given site is dependent upon the interaction of plant and environment throughout the whole of the life-cycle, at the stages of germination, establishment, vegetative growth, flowering and the setting of viable seeds. He points out that the elucidation of the way in which a species thus interacts with its environment can most profitably be investigated by experimental methods. This work represents an attempt to investigate experimentally, using relatively simple apparatus, the basis of adaptation to a rather extreme habitat in a well-defined group of annuals on the Derbyshire limestone. As annuals, their survival in any locality depends upon the successful accomplishment every year of all the above stages whatever the seasonal and yearly variations of climate. Despite this variation the life-cycles are remarkably similar and constant: germination invariably takes place in the early autumn, usually in midor late September; vegetative growth then proceeds until some time in December and with the onset of more favourable conditions in the spring, flowering occurs; seeds are shed in May or June but no germination takes place until the following autumn. As will be seen later, this life-cycle fits rather well into the local climatic pattern, but its significance and the way in which it is controlled was not at all obvious. The habitat is very clearly defined as the species are only to be found on shallow soil in open, sunny situations. On the Derbyshire limestone these conditions are provided in abundance on rock ledges, screes, etc., with a more or less southerly aspect where the annuals in question form a distinct community. Sociologically, therefore, the situation is very simple, particularly as competition between individuals or species is almost nonexistent. The following species may be included in the community, varying somewhat in abundance:

Part II. A Faience Cylinder

In 1939 we cleared away the prickly oak scrub and excavated the rock ledge below the north temple terrace on the north summit of the acropolis of Mycenae. Here we found on the edge of the steep rock remains of a wall of largish blocks of limestone. These we believe to have been part of a Middle Helladic fortification wall running round the upper part of the acropolis. Behind this and held up by the wall were the ruins of two rooms and a thick deposit of M.H. pottery. Over this lay another stratum in which L.H. IIIB pottery was found. Here we found the splendid ivory group of two women and a boy which has already been published. Associated with it were a number of other objects, a male head in painted stucco, a sword pommel in white stone, some ornaments of gold and ivory, a number of beads of stone, paste, and faience including a lantern bead, and a cylinder of faience. The pottery, as stated, was of the L.H. IIIB style, but it was unfortunately lost in the Nauplia Museum during the war.This collection of precious objects we suggested might have belonged to the Shrine of the Palace, which we believe can be be recognized in a small room with a cement floor underlying the western foundations of the temples built here in classical times over part of the ruins of the Mycenaean Palace.

Investigations, areal and engineering geology; Folsom Dam Project, central California

The case of Folsom Dam emphasizes the need for geologic reasoning in the site location, planning-design, and construction phases of multi-purpose projects. Construction afforded an unusual opportunity to evaluate current exploration techniques in highly fractured and deeply weathered granitic and metamorphic rocks.The project totals 4.8 miles of dam and consists of: an overpour gravity section with partially enveloping earthfill wing dams on the American River; Mormon Island earthfill dam across an ancestral channel; eight smaller earthfill saddle dams on tributary drainages; two diversion tunnels; and appurtenant structures.The main dam and most of the saddle embankments are founded on quartz diorite (Upper Jurassic). Metamorphic rocks of the Amador group (Middle-Upper Jurassic) form the foundation at the Mormon Island site. In addition to weathered bedrock, overburden consists of Recent mining debris and Pliocene (?)-Pleistocene channel gravels. The quartz diorite is extensively fractured by a complicated joint system; locally the closely spaced joints simulate a shear or fracture zone.The erratic weathering of quartz diorite constitutes a serious foundation and excavation problem. Commonly outcrops proved to be residual boulders underlain by highly weathered rock to considerable depths. The composition and origin of minerals in the fresh and weathered stages (slight, moderate, highly) of quartz diorite are tabulated for use in predicting the conditions at new sites involving similar rock; megascopic and microscopic criteria for subdividing the weathered rock are correlated with their respective engineering-physical properties. The most important factors controlling the depth and extent of weathering are: spacing of joints and fractures; degree of microfracturing; and the physiographic history of the area.Geologic investigations included a variety of subsurface techniques, i.e., borings, man-sized openings, geophysical surveys, and use of a bore hole camera. Several limitations became apparent with conventional exploration techniques; data from man-sized openings supplemented the cored borings.At the main dam, foundation excavation was performed in three contract stages; conditions exposed at subsequent levels aided in estimating the final foundation. The extremely varied excavation and final foundation rock are recorded in an exploded stage diagram; actual subsurface geologic features of typical lift surfaces are correlated with logs of cored borings and resistivity survey data. Three sizeable fault zones traverse the foundation; special dental treatment and added excavation exposed unquestionable foundation rock.The core trench of many earthfill dams was grouted on the split-method pattern. Adequate grouting of the highly weathered quartz diorite (moderately permeable) proved difficult due to its inhomogeneity and clayey-filled fractures. At Mormon Island, innumerable springs issued from the schistose foundation and necessitated a grout curtain to a depth of 60 feet.Sources of construction materials consisted of: (1) natural aggregate and pervious fill from alluvium deposits; (2) impervious earthfill borrowed selectively from outcrops of highly weathered quartz diorite; and (3) rip-rap of quartz diorite from the main dam, power house and tailrace excavations.To gain additional power head, the natural channel was lowered and the power house placed in a deep excavation. Geologic problems inherent to the excavation included design of a 250 foot open-cut slope and treatment of fractures and joints in a rock ledge between the spillway channel and partially underground power plant.

The Raising of Intertidal Algal Zones on Fair Isle

Fair Isle lies (59? 35' N.-44? W.) off the north coast of Scotland, 20 miles south of the southern tip of Shetland and approximately half-way between Shetland and Orkney. During the course of a preliminary survey of the marine algae on the coast of Fair Isle at the end of June 1952, it became obvious to the authors that the algal vegetation of the island differed in many respects from that found on other parts of the British coast with which they were familiar. The position of the algal zones in relation to tide levels particularly showed features of interest when considered in relation to the sea and atmospheric conditions of the island. The stormy sea conditions and the prevalence of low cloud and fog during the summer months of the year (see Fig. 1) seemed to be of great importance in influencing the occurrence of algal vegetation on the shore. In such an open-sea position, swift tidal currents, meeting the steep cliffs which compose the greater part of the coastline of Fair Isle, produce surf even on the calmest day. On the steepest cliffs only a limited algal vegetation is found, owing, no doubt, to the considerable battering by enormous waves during gales. The authors were unable to make a close inspection of such cliffs, because, although the weather was fairly calm during the period of the survey, there was no day when it was sufficiently calm to use a small boat. In places where the cliffs inclined from the vertical and resolved into series of sloping walls and rock ledges, an algal vegetation was found in which zones, normally intertidal in position, extended far above high-water mark. In illustration of this a survey was made (as detailed as possible under the very difficult working conditions) of a steep exposed area of shore at North Gavel, Bu Ness (Fig. 2, point B). For comparison with it a second survey was made on the north side of the sheltered bay of North Haven (Fig. 2, point A). The method of survey was the same in both areas and was based on a transect line. A chain was thrown through the intertidal region along the chosen line and vertical and horizontal distances were worked out by means of 2 m. rules. Any more accurate method was precluded by the severe working conditions. General views of the North Gavel area are shown in P1. 15. In recording the presence of plants on the transect lines, the rock

Earthenware and Steatite Vessels from Northwestern Wyoming

In the late summer of 1952, as the author was breaking camp at conclusion of the Smithsonian-Princeton field investigations at the Horner site, near Cody, Wyoming, a large earthenware vessel was brought to him for examination. According to its owner, Mr. Don Marquess, the vessel had recently been found “ … under an overhanging rock near Goff Creek Lodge, which is located 43 miles from Cody, Wyoming, on the North Fork of the Shoshoni River, 10 miles from the East gate to Yellowstone National Park. The ledge of rock under which it was found is on the bank of Goff Creek, a mountain stream which runs through the camp and empties into the Shoshoni River. The bottom [of the pot] was protruding slightly from the surface of the ground. The rocks under which it was buried are of a flat nature of various sizes …” (Marquess to Wedel, letter of October 31, 1952).

THE PHYSIOGRAPHY OF AN AREA ADJOINING CAPE MACLEAR

The level ground or isthmus at approximately 200 ft. (61 m.) above sea-level at Cape Maclear is not regarded as a wave-cut platform it its present form, neither are the sandstone ledges and rounded pebbles on the slopes to the north considered to be raised marine benches and beaches. The isthmus, which coincides with a synclinal axis in the Table Mountain Series, was cuestiform until built up by blown sand from the north-west. On the Palaeolithic site to the north this sand invasion occurred during the Middle Stone Age. The cliffs in the west date from the Minor Emergence of Krige (1927) and the rock ledges and caves at Cape Maclear and Cape Point denote a pause at between 12 and 14 ft. (4 m.) in the subsequent withdrawal. The dune invasion which followed suggests that the regression continued below present sea-level, so indicating an interglacial age for the Minor Emergence and the succeeding sub-stage. A shingle beach which marks the limit of the succeeding recovery of sea-level may embrace a small post...

Leucocytozoon bonasae in Ruffed Grouse; Its Possible Relationship to Fluctuations in Numbers of Grouse

During the summer of 1949, Canada geese were observed by pilots, survey crews, and the author on the Colville River, from the headwaters to the 70th parallel on the arctic slope of Alaska. Reports by Eskimos that the geese nest on cliffs of the river was confirmed by locating a single nest and seeing a number of paired birds on the steep north banks. The banks are almost vertical and capped with overhanging tundra. The base continually sloughs into the river during periods of intense flow. The slopes are barren except for scattered bunches of grass and an occasional patch of willow. Climbing the 50to 300-foot slopes is treacherous. A search of about 10 miles of bank resulted in finding only one nest but geese were flushed from many inaccessible points. The nest (July 9, 1949) was in the open, 45 feet above the turbulent water and 50 feet below a rock ledge. The incubating goose was not flushed but the mate was nearby and left the scene. Geese were seen and flushed from similar locations along the Colville. The cliffs of the Colville are undoubtedly a favorite nesting site of the Canada goose in the Arctic. Non-breeding birds were observed on the river bars. Weights and measurements of five nonbreeders, banded on July 12 and 13, identify the species as Branta canadensis leucopareia. A survey party located a nest with 6 eggs on the Etivluk River on July 5, 1949. Accepted for publication January 9, 1953.

Dotsero and Manitou Formations, White River Plateau, Colorado, with Special Reference to Clinetop Algal Limestone Member of Dotsero Formation

Recent field investigations in the White River Plateau of central northwestern Colorado have shown that the age of a sequence of limestone, dolomite, and limestone flat-pebble conglomerate is Late Cambrian and Early Ordovician rather than Late Cambrian only, as formerly designated. The thickness of the sequence ranges from 185 to 251 feet, and the rocks are widespread on the top and flanks of the White River Plateau. The entire sequence was formerly placed in the Dotsero dolomite. It is here divided into the Dotsero and Manitou formations. The Dotsero dolomite is redefined as the Dotsero formation, which includes only the lower part (Late Cambrian) of the former Dotsero dolomite. The upper part of the former Dotsero dolomite is here placed in the Manitou formation of Earl Ordovician age. The Dotsero and Manitou formations contain two members each. The upper member of the Dotsero formation, the Clinetop algal limestone, is a unit composed of algal limestone and limestone conglomerate, commonly 3-5 feet thick, that persists throughout the White River Plateau. It forms a conspicuous ledge of bone-white rock that has a pale lavender tint and a distinctive swirl pattern on its top surface. Fossils from both formations were collected by the writers in 1947 and 1948, and 23 collections were made by the writers and A. R. Palmer in 1951. Upper Cambrian fossils identified by Palmer in these collections consist of 1 species of alga, 2 species of sponges, 2 species of graptolites, 8 species of trilobites, and undeterminable fragments of pelmatozoans and of inarticul te and articulate brachiopods. The Lower Ordovician fauna consists of 1 species of graptolite, 4 species of brachiopods, 5 species of gastropods, 1 species of cephalopod, 13 species of trilobites, 5 species of conodonts, pelmatozoan fragments, and sponge spicules.

Birdshead Cave, a Stratified Site in Wind River Basin, Wyoming

Birdshead Cave lies in a fault scarp on the south side of the Owl Creek Mountains about 5 miles west of the entrance to Wind River Canyon, 23 miles north and west of Shoshoni, Wyoming, and 1 mile northwest of the old Burgess ranch buildings. It contained stratified deposits representing seven, perhaps even eight or nine, periods of occupation in six occupation levels covering a wide temporal range. The cave is approached by steep talus slopes broken by limestone rock ledges. It lies about 200 feet above the source of a spring of fresh, potable water emerging near the base of the scarp. The name, Birdshead, is that of an Arapaho Indian who was living at the old Burgess ranch, now part of the Arapaho Indian Reservation.

A Trip to a Station for Hymenophyllum in South Carolina

My first trip into the mountains of South Carolina in search of filmy ferns, which at the time were1 rumored to be growing there, was made during August, 1937, with Lane Barksdale. We botanized along the Keowee River and some of its tributaries in the vicinity of Jocassee in Pickens County. While in this interesting region we travelled for a number of miles through dense, humid forests, traversed many ravines whose banks were covered with the once mythical Shortia galacifolia T. & G., and forded deep and swiftly flowing streams in some of the gorges which are so numerous in the Southern Appalachians of South Carolina. We found many interesting species of ferns and flowering plants and an abundance of liverworts and mosses covering the rock ledges and rock faces which we examined, but not a vestige of filmy fern could we find.

Analyses of the Stomach Contents of Two Species of Idaho Lizards, with Special Reference to the Formicidae

Little is known of the feeding habits of lizards in general and of Uta levis Baird and Girard (Cliff Uta) in particular. In southern Idaho this species is apparently exclusive to the hot dry rock ledges in the deep Snake River Canyon near Twin Falls. The Cliff Uta seems to be restricted to this type of habitat for it has never been found on the adjoining sandy semidesert. In such a rocky habitat it abounds in New Mexico, Arizona, and southern Utah. This is apparently the first record of its appearance in Idaho. According to Woodbury (2) no study has been made and no account published of the food of Uta levis . He believes it to be an insectivorous lizard. The data presented in this paper confirm his presumption.

Collecting Hepatics along Lake Superior in Northern Minnesota

I have been asked by your Secretary to take you on a collecting trip. The weather is inclement, the distance is great, the season is past. Let us use the magic of memory. We are all at the Head of the Great Lakes. It is August Ist. We are off, at sunrise, in motor cars with camping outfit and food, for a collecting trip along the north shore of Lake Superior from Duluth-Superior to Pigeon River, the International Boundary. For the first 25 miles to Two Harbo s the road is of concrete and skirts the lake shore, with the morning sun glistening the white breakers of the deep blue water. From Two Harbors the Arrowhead Highway winds in and out along the bays, through rock cuts of the headlands and palisades, and the land side becomes more wooded. At Silver Creek cliff we stop to read a memorial tablet, in memory of the early French Voyagers who passed this way long before the New England Colonies, and we realize that we are in an old but ever new country. The road winds about the rocky cliffs, across rivers and deep-cut rock gorges, and by waterfalls. Small mountains are on the left and Lake Superior ever in sight on the right, with palisades, islands, and small sheltered beaches where we can stop for a pocket full of agates. We stop at Gooseberry River to see the falls and the gorge, and to collect. Some of us find Nardia hyalina, Preissia quadrata, Lophozia Kaurini, L. badensis, Plagiochila asplenioides. Some of us come back with fragrant fern, W.oodsia alpina, Woodsia ilvensis, and yard-long fronds of bladder ferns. The woods are dry from sun and fire and we go on through ever changing scenery of lake shore, rocks, rock-topped hills, over rivers, gorges and by waterfalls, to Cascade River where we stop for lunch, on the shelving rocks of the lake shore. We leave with reluctance the Cascade, with the dozen of waterfalls and trout pools set in a virgin forest. We find that the north shore range, stretching from Duluth to Port Arthur, rises to an elevation of 600 to 700 feet above the level of the lake shore to one mile west, and is cut by many rivers, which make the drop to the lake level, near the lake. We pass many waterfalls and deep gorges. However, the forest is mostly second-growth, and fire and drought have destroyed much of the original growth of bryophytes. We reach Grand Marais in the afternoon and rest at hotel or camp site. Near this village a circling beach ends in a rocky peninsula, almost an island, which proves to be a paradise for Bryophytes. An acre in extent, the area is broken by rock ridges well covered witl humus and which support a rich growth of spruce, balsam and cedar. The surface is wet and the depressions swampy. The ground cover is of Ledum, sphagnum, mountain cranberry, and mosses. The bare rocks are richly covered with lichens, and the seams of rock ledges are outlined by Primula mistassinica and pinguiculas: a typical northern heath bog set on top of a rocky island. The lake side is a level slope or rock; the northwestern side a broken ledge of trap, and it is here that we find a surprising growth of hepatics. The place was first visited by a Wisconsin botanist, L. S. Cheney of the University of Wisconsin, in I889. He found 84 flowering plants, 41 mosses, and 7 hepatics near Grand Marais.

Plant Communities of Alpine Park

1. The area described is located near Logan Pass in Glacier Park, Montana, and consists of a level tract about one mile square between mountain peaks, at an average elevation of 7000 feet. 2. Four physiographic formations were found: a grassy steppe dotted with clumps of conifers, a wet Arctic meadow between low rock ledges, a glacial moraine formation, and a rock terrace formation. 3. The xerarch succession of these communities proceeds from pioneer stages on the glacial moraines, to grass steppe dotted with conifer clumps. The steppe seems to represent a temporary climax, with the conifers as a possible later stage under more favorable conditions. 4. The hydrarch succession develops in ponds left by the melting glacier, but does not proceed further than a wet meadow stage.

Plant Composition and Soil Acidity of a Maine Bog

Mt. Desert Island lies off the eastern coast of the state of Maine in latitude 440 north and longitude 680 west. The island is of peculiar interest on account of its unusual assemblage of plants and animals, and its remarkable influence on man.2 The predominant vegetation is northern, with a number of arctic alpine plants, a few of which elsewhere in this latitude occur only above timber line; and yet there is a mixture of southern forms. The same mixture of northern and southern forms is found in the insect fauna of the island. There are here presented brief observations on the plants of a small bog on the south side of the island near the village of Bass Harbor. The bog in question is about fifty yards long by twenty-five wide and appears to be due to an undrained depression in a wide granite ledge. The granite, which comprises the hills of the island (extending over I,500 feet elevation) and much of the more level parts, is pink in some places and gray in others, and rather coarsely crystalline. It cooled at a considerable distance below the surface and was later exposed by erosion.3 The granite in this case was pink, made up of quartz, potassium feldspar, a little mica, and hornblende. The bog proper contains no open water and is covered chiefly with sedges. Around the margin of the bog is a stunted rather open growth of black spruce with a mixture of larch, Larix laricina, and a little Arborvitae, Thuja occidentalis, none of the trees exceeding ten feet in height. A few feet beyond this margin there are in places outcrops of the granite ledge on which grow plants of peculiar interest. Three sites, quite different edaphically, are represented in an area not exceeding an acre in size. Two of these sites, the bog proper and the rock ledge, are xerophytic, the former from lack of moisture, the latter from the character of its water. The marginal site, or forest, which merges with the surrounding forest, is mesophytic.

Occurrence of Funaria hygrometrica (L.) Sibth.

One of the most interesting of mosses from the viewpoint of the ecologist is Funaria hygrometrica (L.) Sibth. It is cosmopolitan, appears in great abundance in various soils, and is a prolific sporophyte producer. It is probably because of its wide distribution and ease of recognition, that we find it given as the type species in many elementary texts of Botany, and in many respects it is admirable for this purpose. Within the city limits of Chicago we find it as a pioneer crevice-species on rocks and in cracks of the cement walks. In the vicinity of the city it can be found in cracks of stone walls and in crevices of small rock ledges. It is equally at home on cinder piles along railroad embankments and on old ash heaps. It has been found fruiting on areas on which rubbish had been burned during the previous season, and along the gravel walks in Lake Park in the city of Milwaukee.

Notes on a Few Birds of the Grand Canyon, Arizona

The ground is cold as a marble pavement. The abundant leaves of the red-bud bear too intense a shade for a pre-sunlit morning; the dense clusters of seedpods hang luxuriantly from the twigs. Across the path, at the base of the bank, the Indian paint brush glows between the softer-toned blossoms of the mallow, and the yellow plume of the Stanleya, to which the hummingbirds have not yet darted. in a dark, little niche, overhung by grape-vines, one beautiful, solitary thistle poppy blooms. Suddenly, I hear a vibrant hum in the air, mingled with excited twitterings, and shrill squeaks. Buzz, buzz, buz-z-z ..... over the willow tips, over the tules, over the graceful stems of the tall, waxy-flowered dogbane. Then, I catch the gleam of two little sprites of the air-Black-chinned Hummingbirds (Archilochus alexandri), chasing one another with miraculous speed. The combat ceases as abruptly as it commenced. The contestants separate. One retires to a grape-vine swing and sits there quietly, occasionally shaking his ridiculous tail feathers; the other descends to the pool. He dips his little breast into the shallow water; he rises into the air; he drops again by gentle stages, twirling around after each descent, and squeaking ominously; he dips again, and submerging his tiny body to the chin, he trails through the pool like a fiery ship of green and violet. While he perches on a horizontal stem of dog-bane to dry his feathers, I gaze about me in quest of other birds. A male Black-headed Grosbeak (Zamnelodia melanocephala) is softly singing on a willow bough which overhangs the pool, while his mate is surreptitiously collecting a bundle of fiber from a dried plant on the opposite bank. Dark shapes flit constantly about the latter, and, by the aid of my field-glasses, I can discern several pairs of Desert Sparrows (Amphispiza bilineata deserticola) apparently nesting in the cactus and other growth on the hillside. The Black-throats' song, strung upon three tones, is rather thin and wiry, but especially suited to their environment. Far above these little sparrows, almost at the foot of the massive wall of rock which towers beyond them, several wild burros, escaped from cultivation , are leisurely grazing. Almost indistinguishable are they, in their coats of gray, from the boulders and brush amongst which they slowly move. As I watch them, an insect-like trill floats to me from a ledge of rock, lower down the hill-side, and, by carefully focusing my glasses upon the spot. I can descry the Rock Wren (Salpinctcs obsoletus), standing by a clump of cactus, and jerking her body up and down by what seems to be a well-managed system of wires. Very evidently, she is nesting in the fissure of rock, as she returns again and again to that particular spot, while her mate calls to her from some hidden point of vantage nearby. A rock squirrel runs along a ledge above her, sits up meditatively, drops again, and scampers into a crevice. And yet the sun has not risen behind me, over that austere barrier of rock. The air is still cold, and not a single lizard has stirred.

A Preliminary List of the Ferns of Rolla, Missouri

along the streams. The lowest formation is the Gasconade with its cliff-forming dolomite. Near the Gasconade River this formation produces some fairly high and steep bluffs. The ferns found, as may be judged from the above statements, are chiefly rock-loving species. Further search will doubtless reveal some lowland species and the dry Gasconade cliffs should add several to the list. The most interesting find to date is Ophioglossum Engelmanni. On June 20, the writer found, in a hollow one mile west of Rolla, several thousand plants of this species, many of which were in fruit; on some plants the spikes had turned brown and on others had not yet attained the length of the leaf. Fertile plants three or four to eight inches long were found. The pitted dolomite mentioned above here forms a low cliff, back of which, away from the branch, is a small bench carved from the cotton rock. On this bench, for about one mile down the hollow-the distance examined-the adder's tongue was very abundant among the rocks, growing in a dry, sterile soil. A few plants were found in the narrow bottom near the stream where the rock ledge dips below the water. Onoclea sensibilis. One colony of this species was found growing on sandstone in the bed of a creek.

The Lower Rapids of the Mississippi River

Previous articleNext article FreeThe Lower Rapids of the Mississippi RiverFrank LeverettFrank Leverett Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Journal of Geology Volume 7, Number 1Jan. - Feb., 1899 Article DOIhttps://doi.org/10.1086/608284 Views: 48 PDF download Crossref reports no articles citing this article.

The Juba River

AT the meeting of the Royal Geographical Society on Monday evening, Commander F. G. Dundas, R.N., read a paper describing his ascent of the Juba river. This was the first serious attempt to explore the river since Von der Decken's illfated expedition in the Guelph in August, 1865. The stern- wheel steamer Kenia, belonging to the Imperial British East Africa Company, under the command of Captain Dundas, crossed the bar of the Juba on April 25, 1892, an operation of much danger, as the vessel was exposed broadside on to heavy rollers; the depth at high water is only one fathom, and the water swarms with sharks and crocodiles. The coast Somalis lined the bank with hostile movements as soon as they saw that the vessel was to go up the river, and detained the expedition for a fortnight, until a message was sent to the head chief, the Sultan of the Ogaden Somalis. It was July 3 before amicable arrangements could be made, and the expedition fairly started. The Somalis met with everywhere were very strict Mohammedans, and secluded their women, but a number of Galla slave-girls were seen amongst them. There were few villages, Hajowan and Hajaualla opposite each other near the mouth being the only large ones until Munsur, 360 miles, and Bardera, 387 miles from the sea, were reached. The lower reaches of the river were very winding. On one occasion Captain Dundas observed a stream flowing parallel to the river he was on, and going across to see it recognized the landmarks as those he had passed three hours before. The Waboni tribe, who live by hunting, and use the bow and arrow, occupied the thick woods of the lower river. Above them the curves became more gentle, and the Gusha district was reached, where the people cultivated the land, which was cleared by burning; and for a hundred miles the Kenia's furnaces were fired with the dead trees which had been killed, but left unburnt by the fire. Cotton is cultivated as well as food plants, and there is a primitive system of weaving. Above Bilo, and about 100 miles from the sea, a branch was found to run off from the main river to the south-west through very dense forests. This is probably the Sheri, which reaches the sea midway between Lamu and Kismayu; the land between this and the Juba mouth being probably of deltaic origin. This branch was explored in a boat for twenty miles. The dense forests formed a broad belt on both sides on the river, and after steaming for five days through uninhabited woods the Kenia suddenly emerged into open country on August 2. The people were of very mixed race, friendly and well supplied with all sorts of food. Hills began to appear, and the river grew shallower, until on August 10 the steamer moored to the batik opposite Bardera. Here the Sultan forbad a landing, and the people, who numbered about 1200, were hostile, but ultimately peace was arranged, and one of the subordinate sheiks accompanied the Kenia to the rapid, where the river sweeps between steep rocky hills 300 to 400 feet high. There are three channels in the rapids, but at the time of the visit none was navigable, and the natives reported a waterfall over a ledge of rock about four hours' march further up, in latitude 2°34′ N. The wreck of the Guelph was visited and examined, but the rapid falling of the water made it necessary to hasten back to the sea. The climate throughout was found agreeable, and there were few mosquitoes. The river does not overflow, so there are no malarial swamps along the banks.