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NA TURE 



\May 30, 1889 



GEOGRAPHICAL NOTES. 



At the anniversary meeting of the Royal Geographical Society 

 on Monday, the medals and other honours already announced in 

 Nature were awarded. Dr. Kadde, of Tiflis, appeared in 

 person to receive his medal, which he acknowledged briefly and 

 appreciatively. The address of the President, General Strachey, 

 was of more than usual interest. After referring to the geo- 

 graphical events of the year, he took up the subject of Central 

 Africa, its future exploration, and its subjection to the commercial 

 and civilizing influence of Europe. General Strachey reviewed 

 the results of European contact with the various other parts of 

 the world, savage and semi-civilized. "There is no room to 

 doubt," he said, " that the occupation of the earth by man in the 

 many various modes presented to us has been determined mainly 

 by the physical conditions of the surface, the distribution of land 

 and sea, and the nature of the climate, operating in conjunction 

 with the particular inherited capacities of the several branches of 

 the human race, which have themselves been largely determined 

 by these same physical conditions. The diffusion of races, and 

 their more or less permanent occupation of various parts of the 

 earth, have necessarily been regulated by their relative powers of 

 adapting themselves to, and taking advantage of, the facilities for 

 existence offered by the regions they occupied, and of resiting ad- 

 verse pre- sure of all sorts brought to bear upon them from without. 

 Among the best safeguards against that form of pressure which 

 consists of the intrusion of other races, have ever been i-olation 

 by the ocean, or by high mountains, great land distances, forests 

 and deserts ; ar.d hence it has been that the interiors of the great 

 continents have for the most part been last explored, and their 

 inhabitants least disturbed. As the first of these defences was 

 weakened by the development of the art of navigation, the pro- 

 gressive r.aces of Europe began to seek for fresh scope for their 

 activities in many distant regions, thus for the first time rendered 

 accessible to them. From very small beginnings within the 

 Mediterranean, which for several centuries gained strength only 

 by slow degrees, at length burst forth some 400 years ago the 

 stream of conquest and com.mercial adventure which has in our 

 time been carried across every part of the ocean ; and has beaten 

 on all its shores, throwing open an infinitude of lines of attack 

 for the inroads of European progress upon regions previously 

 resting in various conditions of relatively primitive stagnation." 

 General Strachey then, in a highly suggestive manner, reviewed 

 the methods and results of European conquest or European 

 civilization in North, Central, and South America, Australasia, 

 In:lia, China, North Africa and South Africa, and, coming 

 finally to Central Africa, he pointed out that the conditions 

 there were peculiar and required peculiar treatment. "The 

 vastarea of tropical Africa," he said, "its climate, ■ often so 

 hostile to Europeans, and the numbers and character of the 

 population, combined with the peculiar difficulties attending 

 all transport in the interior, have retarded the progress of 

 geographical discovery, and obstructed that intercommunication 

 between neighbouring districts which supplies the natural 

 machinery by which the progress of the les3 advanced races is 

 carried forward. It is impossible to suppose that the impression 

 to be made on these countries by the mere handful of men of 

 northern race who are now scattered along its coasts or at a few 

 points in its interior, can be anything but extremely slow, and it 

 is hardly less certain that under the wholly different conditions 



that Central Africa presents from those of any other country 

 hitherto brought within the operation of the process of civiliza- 

 tion, the form which that process will take, and its results, will 

 be very different from anything that past experience can suggest. 

 The possibility of any colonization by direct immigration on such 

 a scale as to produce effects in any way analogous to those ob- 

 tained in North America or Australia is obviously excluded ; the 

 condition of the people over the greater part of the continent 

 renders it equally impossible to look forward to a time when 

 systems of administration at all approaching that of India could 

 be established ; and amalgamation between European settlers 

 and the indigenous races appears no less out of the question. 

 The operation of bringing a population such as that of Central 

 Africa under the restraints of civilization will necessarily be a 

 long and no doubt in some respects a painful one, for assuredly 

 the conflict with slavery, cannibalism, and massacre cannot be 

 carried to a successful issue by gentle means alone. The dangers 

 that attend precipitation, with consequent reaction, have been 

 already exemplified too plainly, and by the sacrifice of too 

 many noble lives ; and in circumstances such as those that here 

 have to be dealt with, toleation of unavoidable evil at the outset 

 may well afford the best and most certain means of introducing per- 

 manent improvement. Nor can I see any reason to question the 

 conclusion that the best method of entering on this gigantic task 

 is that which the general sense of Europe has practically resolved 

 to adopt — namely, to form commercial associations intrusted 

 with the exercise of reasonable administrative authority within 

 the several areas assigned to them, hoping that thus the African 

 population may by degrees be taught that the path to social and 

 material comfort and well-being lies through well ordered in- 

 dustry and peaceful occupations ; in imparting which lessons 

 the earnest co-operation of the many purely philanthropic 

 missions already established among these people may be most 

 confidently counted on." 



BEACON LIGHTS AND FOG SIGNALS.'' 



II. 



TN 1876, Mr. Julius Pintfch, of Berlin, patented in this country 

 his system of illuminating buoys or other floating bodies by 

 compressed oil gas, and in 1878 one of these buoys was experi- 

 mentally tried at sea with success by the Trinity House. The 

 system is similar to that previously adopted by Mr. Pintsch with 

 great success in the lighting of railway carriages, but with the 

 addition for buoys of a specially constructed lantern, containing 

 a small cylindrical lens for fixed light. Through the kindness 

 of the Pintsch's Lighting Company, we have here one of these 

 apparatus, producing an intensity in the beam of about twenty 

 candle units. With the charge of gas contained in the buoy, the 

 light is shown continuously, night and day, from two to four 

 months, according to the dimensions of the buoy, without re- 

 filling or requiring any other attention except occasional cleaning 

 of the lens and the glazing of the lantern. In 1883, Mr. William 

 B. Rickman patented a very ingenious addition to this apparatus 

 for producing occulting or flashing light. The apparatus is 

 automatically worked by the issuing compressed gas on its way 

 from the buoy to the burner. After passing the regulator where 

 the pressure of the gas is reduced for burning, it enters a cylin- 

 drical chamber covered with a diaphragm of very flexible specially 

 prepared leather, this diaphragm, on being slightly raised by the 

 in-flowing gas, communicates motion to a lever, which, assisted 

 by a spiral spring, closes the inlet pipe, and opens at the same 

 time the passage to the burner. As the gas passes on and 

 is consumed at the burner, the diaphragm by its own weight, 

 assisted by the spring, sinks, and touching the lever, closes 

 the outlet aperture to the burner, and at the same moment 

 opens the inlet of the gas from the buoy for another charge. 

 Thus the light is extinguished while the gas is entering the 

 chamber, and until the latter is refilled, when the passage 

 from the buoy is again closed by the rising of the diaphragm. 

 A small pilot jet is constantly burning to insure the re-ignition 

 of the gas when re-admitted to the burner. It is evident that 

 several characteristic distinctions of light may be obtained by 

 modifications of this ingenious apparatus. About 150 buoys 

 lighted on the Pintsch system are already rendering valuable 



' Friday evening discourse delivered at the Royal Instituti on by Sir 

 James N. Douglass, F.R.S., on Msrch 15. Continued from p. gi 



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