February 27, 1902] 



NA TURE 



397 



Bohemia, was of Czech descent. He was born in the 

 small town of Holies on October 7, 1S47. After prac- 

 tising for a time as an apothecary, his scientific leanings 

 and his adventurous spirit led him, at the age of twenty- 

 ■ five, to emigrate to South Africa. His principal induce- 

 ment to explore the land beyond the Zambesi was his 

 love of natural history, and more particularly his interest in 

 ornithology. Indeed, the first period of seven years spent by 

 him in South Africa was mainly devoted to ornithology and to 

 zoology in general. On his return to Europe he tooii up his 

 residence at Prague, and afterwards in Vienna, where he pre- 

 pared his "Beilrage zur Ornithologie Siidalricas " ("Contri- 

 butions to the Ornithology of South Africa") A little later 

 he published "Seven Years in South Africa" and "The 

 Colonisation of Africa." .Vt this time he devoted himself 

 seriously to the study of astronomy and geography, having 

 during his first journey been greatly hampered, as he was always 

 the first to confess and deplore, by his lack of physical and 

 mathematical knowledge. His explorations, therefore, had 

 been rather those of a zoologist than of a geographical explorer. 

 Having resolved to overcome this difficulty, he set to work, 

 and when, in 1SS3, he landed on African soil for the second 

 time he was probably as well equipped as any of his prede- 

 cessors in African exploration. After a little delay, Dr. Holub 

 proceeded to the country o( the Mashukulumbe, into which he 

 penetrated further than any European had done before him. 

 There, accompanied by his wife, he spent four years, returning 

 to Europe in 1887. His book, entitled " From Cape Town to 

 the Country of Mashukulumbe," which contains a record of 

 his labours, has become a standard work. Like his former 

 publications, it has been translated into many languages. 



The German Physical Society's publication, Die Forlschritte 

 tier Physik, has, under the editorship of Profs. Scheel (for pure 

 physics) and Assmann (for cosmic physics), fiirly succeeded 

 in attaining the maximum efficiency in keeping up to date with the 

 most recent papers, consistently with its appearance as a yearly 

 volume. In order to accelerate further the issue of a summary 

 of current literature, Messrs. Fried. Vieweg and Son, of Bruns- 

 wick, now announce the publication, in connection with the 

 Fortsihrilie, of a Halbnioiialliches Lil'.eratiirx'erzeichiiiss, which 

 will furnish the physicist at fortnightly intervals with a list of 



determines the velocity. When the experiments were repeated 

 under identical conditions, the two images were found to agree 

 to such an extent as to be capable of superposition. 



In connection with the wreck of Santos Dumont No. 6, 

 Dr. J. V. Buchanan, F.R.S., has written a letter to the Times 

 which may serve to correct any false impressions that may have 

 been formed as to the value or general conclusions of the ex- 

 periments. It is pointed out that "to M. Dumont himself 

 every fresh ascent, whether the public term it a success or a 

 failure, is full of lessons on a quantity of matters of detail of 

 which the uninitiated can have no perception. Indeed, the 

 more complete the apparent failure, the greater is the value of 

 the experience to the air pilot, provided he escape so as to be 

 able to utilise the experience himself." Since Dr. Buchanan 

 arrived at Monaco, M. Dumont has taken his balloon out three 

 times. The first time (on February 10) the balloon completely 

 outstripped the Prince of Monaco's launch, and was even esti- 

 mated to achieve 15 knots relative to the ground, going against 

 a breeze. But " the most striking and at the same time un- 

 favourable feature was the heavy pitching of the balloon, which 

 at times attained an ampliiude of not far from 45° on each side 

 the vertical. " On the nth, M. Dumont performed his most suc- 

 cessful journey in the direction of Cap Martin and back, the 

 balloon pitching much less than previously. The accident 

 which occurred on the 14th appears to have been mainly due to 

 this pitching. " Arrived abreast the pigeon-shooting ground, 

 the pitching became more violent, and the balloon rose, taking 

 the guide-rope, which usually trails on the surlace of the water, 

 entirely out of the water and to a height of fifty yards or more 

 above it. The situation was now becoming critical. In pitch- 

 ing, the balloon came to be standing very nearly vertically, first on 

 one end and then on the other." M. Dumont appears then to have 

 let out gas, which had the effect of causing the rear and lower 

 end to collapse, and the rudder was thereby rendered useless. 

 From this time until M. Dumont was rescued, wet and bedraggled, 

 from the wreck, frequent photographs were taken showing the 

 form assumed by the balloon during its gradual deflation. 

 Two conclusions are drawn from the experiments ; firstly, that 

 the pitching must be prevented by the application of aeroplanes 

 or side pieces performing the functions of bilge keels, or by 

 other means, and, secondly, the great difficulty attaching to the 



papers and books classified under the various branches of | ellipsoidal balloon as compared with the typical one of spherical 

 physics. The first and second numbers contain forty and twenty 1 or more strictly pear-shaped form, in that the former tends to 

 pages respectively. The titles only of the papers are given, so 1 revert to the spherical shape as soon as it is somewhat deflated, 

 each page contains the names of some five-and-twenty different 

 papers. The subscription price of the Litlei-aliirveizeichniss is 



only 4 marks per annum, so it should soon find its way into 

 the library of every physicist. 



The Bulletin of the French Physical Society, No. 174, 

 describes briefly some important experiments by M. Marey on 

 the motion of fluids studied by photography. In the case of 

 liquids, M. Marey was successful, as long ago as 1893, in study- 

 ing the motions by means of beads of the same specific gravity 

 as the liquid. He has recently succeeded in studying the 

 movement of air-currents past a fixed obstacle by means of 

 smoke filaments, obtained by filtering the air-current through 

 silk gauze with even meshes, the smoke being photographed by 

 means of magnesium light. Where no obstacle exists, the 

 filaments of smoke are rectilinear and parallel, while if an 

 inclined plane be placed in the current, they will be seen to 

 indicate the form of the stream lines, some bending round the 

 upper and others round the lower edge. To obtain the velocity 

 of the current at different points, a lateral oscillatory motion of 

 ten periods per second is given to the screen, when the smoke 

 filaments assume a sinusoidal form which is preserved throughout 

 their path and the distance between the inflexions at any point 

 NO. 1687, VOL. 65] 



hile the latter better preserves its natural form in shrinking. 

 A WRITER in the Dumfries and Galloway Standard and 



Advertiser (February 12) directs attention to a curious anticipa- 

 tion of a magnetic means of communication contained in the 

 following paragraph from the Sptctatoro{ December 6, 1797 :— 

 " Strada, in one of his prolusions, gives an account of a 

 chimerical correspondence between two friends by the help of a 

 certain loadstone, which had such virtue in it that if it touched 

 two several needles, when one of the needles so touched began 

 to move, the other, though at never so great a distance, moved 

 at the same time, and in the same manner. He tells us that the 

 two friends, being each of them possesseil of one of these 

 needles, made a kind of a dial plate, inscribing it with the four 

 and twenty letters, in the same manner as the hours of the day 

 are marked upon the ordinary dial plate. They then fixed one 

 of the needles on each side of these plates in such a manner that 

 it could move round without impediment so as to touch any of 

 the four and twenty letters. Upon their separating from one 

 another into different countries, they agreed to withdraw them- 

 selves punctually into their closets at a certain hour of the day, 

 and to converse with one another by means of this their inven- 

 tion. Accordingly, when they were some hundreds of mile 



