THE TURB A is the Water Whe studied in Germany, and has been too much neglected in England, the Reciprocating Water Pressure Engine. A very powerful machine of this kind was lately made under the direction of the writer, whilst acting as engineer-in-chief to the Butterley Company, by order of our respected treasurer Mr. John Taylor, and erected by Mr. Darlington at the Alport mines, near Bakewell, Derbyshire. A beautiful model of this engine was made by Mr. Jordan, and is deposited in the Museum of Economic Geology; but no description of it has yet been published, and it is a subject well-worthy the attention of the British Association. ILLUSTRATIONS. The drawings show an elevation and plan of Dr. Barker's mill. (See wood-cut.) Plate XXI.-An elevation, plan and section of Mr. Whitelaw's mill, and a diagram showing the mode of forming the spiral curvature of the arms: the section shows a loose collar pressed upward against the revolving part of the machine by three bow springs fixed between the flanches; the collar is prevented from revolving by a steady pin, and the parts in contact are ground together to be water-tight. The double mill proposed by Professor Redtenbacher is also shown as a sectional plan. Method of striking the spiral curves to form the arms. Plate XXII. shows a sectional elevation of a Low Pressure Turbine, with one of the three screws for raising and lowering the circular sluice. The screws are connected and act together by means of toothed wheels. Also a plan of the water-wheel, the guide curves, and a portion of the circular sluice; and to a larger scale a section of the water-wheel, showing the mode of fixing the curved buckets, which are made of thin plate iron, and are screwed against loose blocks or pieces of cast-iron, and these are secured by means of screw bolts within the rim of the water-wheel. Plate XXIII. is a section of the Turbine of St. Blasier; the body of the machine is of cast iron, the wheel is of hammered iron, and the spindle or axis of steel. The foot of the spindle, and the pivot and step on which it revolves, are tempered to extreme hardness. The oil-pipe at the foot of the pivot is connected with a small force pump or syringe, which, at regular intervals, injects a little oil into the step for lubrication; the pump is worked by a slow motion from the machinery. In all cases it is necessary that the foot of the spindle shall be made hollow, and run upon a fixed pivot. The spindle must never run in a hollow step. The pivot should be quite cylindrical, and it should truly fit the spindle, with as little play as possible; the top of the pivot should be but very slightly convex. The water and mud must be carefully excluded, and the parts regularly oiled. Plate XXIV. shows a quadrant or fourth part of the wheel, with the guide curves, and the sluice or regulator of the Turbine of St. Blasier, of the natural or full size of the machine itself; the bent arrow shows the direction in which the wheel revolves. On the present state and recent progress of Ethnographical Philology. By R. G. LATHAM, M.D.* Part I.-AFRICA. THE author has found it necessary to divide his Report upon the present state and recent progress of Ethnographical Philology into separate parts; a process which the nature of the subject renders easy and convenient. By the term Languages of Africa are meant the languages of continental Africa and the Canary Isles. The island of Madagascar is excluded; it being a well-known fact that the philological affinities of the dialects there spoken are with the Malay languages of Malacca, the Moluccas, and Polynesia: so that for philological purposes Madagascar is a part of Polynesia. Furthermore, it should be remarked that no cognizance will be taken of the different Moorish dialects, spoken in northern and eastern Africa, and believed to have been introduced since the time of Mahomet; it being considered that these are only African in the way that the English of the Cape, or the Portuguese of Angola is African, i. e. that they are languages introduced within the historical period, and not the indigenous tongues of the country. Hence all forms of the modern Arabic of Arabia, and, à fortiori, all forms of the Turkish of Turkey are omitted. On the other hand, the Arabic elements of the languages of Abyssinia, although they will not be investigated in the present paper, are proper objects of consideration, inasmuch as they are referable to a period anterior to history, and bear upon the theory of the original population of the continent. In a subject like the present, capable of being thrown into as many natural divisions as there are quarters of the world; a subject, moreover, whereof the several portions have been studied with the most different degrees of attention; the term recent progress has by no means a uniform signification. It differs with the group of languages to which it is applied. A year's research in some *A few days before the following pages were put into the hands of the printer, I met with the new and revised edition of Vater's Litteratur der Grammatiken, &c., by B. Jülg (Berlin, 1847). The bibliographical notices, which I was thus enabled to add to those previously enumerated by myself, are each marked Jülg. To the majority of these I have not had time or opportunity to refer; so that it is possible that they may not all contain either first-hand data, or vocabularies different from some previously mentioned. The general character of Dr. Jülg's work is that it is minute and exhaustive. Of the more important materials for African philology he has omitted only two, Crowther's Yarriba Vocabulary, and Dr. Beke's Abyssinian Vocabularies. |