344 



NA TURE 



[August 7, iSb'.j- 



about fifty or sixty in number, were met at the station by Mr. J. 

 Horace Round, who conducted them through the older parts of 

 the town to the Castle, the history of which was lucidly sketched 

 and the mnin points of interest shown by Mr. Round. A hur- 

 ried visit to the Castle Museum, with its splendid collection of 

 local antiquities and natural history objects, was nevt made under 

 the guidance of the Rev. C. L. Acland and Mr. Round. The 

 party then proceeding to lunch at the Cups Hotel. After lunch, 

 a drive of about eight miles along the Mersea Road, passing 

 through the villages of Abberton and Peldon, the scenes of the 

 earthquake of April 22, brought the party to West Mersea, 

 where Mr. H. Lauer addressed them upon the history of this 

 and the surrounding districts during Roman times, suggesting 

 that the Roman town of Othona may have been situated on the 

 opposite shore of the River Blackwater in the neighbourhood of 

 Bradwell. Mr. Lauer next called attention to the interesting 

 and mysterious " salting-mounds " or " red hills, " which occur 

 also on the Norfolk coast and along the rivers in Suffolk and 

 Kent, and of which eighteen still exist between St rood and Vir- 

 ley in Essex. These, according to Mr. H. Stopes, F.G.S., often 

 cover as much as to to 30 acres, and are from 2 to 4a feet deep, 

 being composed of red burnt clay mixed with rude broken pottery, 

 charcoal, ashes, and often bones. A ramble eastward along the 

 coast of Mersea Island brought the party to the "decoy'' for 

 the capture of wild-fowl, the working of which in former times 

 was explained by Mr. Lauer. Here Mr. J. C. Shenstone gave a 

 short demonstration of the interesting coast flora. Driving 

 homewards the party stopped at the ruins of Langenhoe Church, 

 wrecked by the earthquake, where Mr. R. Meldola gave a short 

 statement on this subject in anticipation of the detailed report 

 which he proposes to present to the Club. He stated that the 

 area of structural damage covered about fifty square miles. After 

 tea an ordinary meeting was held, Mr. R. Meldola in the chair, 

 and the evening concluded with a conversazione at the Hotel, 

 collections of insects, dried plants, and living insectivorous plants 

 being exhibited by Mr. W. H. Harwood, Mr. Shenstone, and 

 Dr. Alexander Wallace. The Mayor and many of the towns- 

 people were present during the evening to listen to the short 

 addresses on natural history subjects given in explanation of the 

 various exhibits. 



The repeated failures of steamers to reach Siberia from 

 Europe do not seem to have deterred M. Sihiriakoff, the well- 

 known Russian merchant, from again despatching two steamers 

 this year. Early last month the steamers Nordenskjold and Obi 

 left Tromsb (Norway) to attempt, it is stated, for the last time to 

 reach Siberia. When in lat. 70 55' N. and long. 52° 15' E. 

 the engines of the Nordenskjold broke down, and she was with 

 great difficulty towed back to Vardo. 



A SUBSCRIPTION has been opened at St. Petersburg, in order 

 to raise the money for instituting at the University five bursaries 

 in the name of Charles Darwin, to be employed for the main- 

 tenance of five students in the five chief branches of natural 

 science. 



The Russian review, Russkaya Starina, and the Jownal of the 

 Russian Chemical and Physical Society have lately devoted 

 some attention to the first steam-engine that was made in the 

 Russian Empire, in 1763, at the ironworks of Barnaoul, in 

 Western Siberia, by a mining engineer, Polzunoff. It appears 

 from M. Woyeikoff s description of this steam-engine, the model 

 of which exists still at Barnaoul (both review's have figured it on 

 plates), that Polzunoff's engine was a reproduction of the " fire- 

 engine " of Newcomen, with some original improvements. Thus 

 it has two cylinders, instead of one, and, instead of the beam, 

 Polzunoff made use of a wheel which received the chains of the 

 pistons, and transmitted the circular movement, transformed 

 again into a rectilinear one, to a pair of bellows, used for 



blowing air into a high furnace. The distribution of vapour was 

 automatic, as in Newcomen's engine, but with several improve- 

 ments. The engine, which had cylinders 9 feet long and 9 

 inches in diameter, worked during two months from May 2c\ 

 1766, and 3100 cwts. of silver ore, yielding 5 cwts. of silver, 

 were melted with its help. But Polzunoff did not see his engine 

 at work, as he died from consumption four days before. He 

 obviously was a remarkable man for his time, several of the 

 physical remarks he made in the description of his engine show- 

 ing not only a wide knowledge, but also a serious spirit of true 

 physical reasoning, together with a notable skill for determining 

 the limits of knowledge of that time. In his theoretical remarks 

 about " Air, Water, and Vapour," he notices also that physicists 

 are not yet agreed as to the origin of heat, some of them seeing 

 in it a much-divided, fine moving matter, while others "see the 

 origin of heat in friction and in the vibratory motion of the 

 particles inaccessible to our senses, of which the bodies are con- 

 stituted." He obviously quotes here the words of Lomonosoff, 

 who stated in these very words the mechanical origin of heat in 

 his most remarkable but unhappily little-known memoir, written 

 as an instruction to Tchitchagoff' s Polar Expedition. 



Several severe shocks of earthquake were felt on Sunday 

 afternoon at Foca, in Bosnia. The duration of each shock was 

 over two seconds. 



A brochure just issued by M. Ch. Montigny at Brussels 

 contains in convenient form the result of his studies on the state 

 of the atmosphere as affecting stellar scintillation, with a view to 

 fun casting the stale of the weather. From the fact determined 

 by W. Spring, that the colour of pure water in great bulk is 

 blue, he explains the predominance of this colour in the scintil- 

 lation of the stars just before and during wet weather. The 

 luminous rays, he argues, traversing the air charged with large 

 quantities of pure water are necessarily tinged with the blue 

 colour of this medium. The excess of blue thus becomes an 

 almost certain means of predicting rain. This theoretic con 

 elusion corresponds with the results of his observations con- 

 tinued for several years past on the appearance of the stellar 

 rays in connection with the state of the weather. During the 

 few months of fine weather in the present year blue has been 

 much less conspicuous than in the corresponding months oi 

 previous years since 1876, when wet weather prevailed. It also 

 appears that green, which had always coincided with clear skies 

 during the fine years before 1876, has recently again become 

 predominant. Hence he thinks it probable that we have got 

 over the cycle of bad seasons, and that dry weather and more 

 normal summers may be anticipated at least for some time to come. 

 Prof. F. Neesen publishes a reprint of his paper in the 

 Archiv filr Artillerie- und fngenitii'-OJ^zure for 18S4 on a 

 generalisation of Sebert's method of registering the velocity of 

 shot within the tube of a gun. Sebert's apparatus necessarily 

 registers for a space somewhat shorter than the diameter of the 

 ball. This defect is remedied and the registration extended to 

 the whole length of the tube by means of a revolving appliance 

 to which the registering tuning-fork is attached, and disposed 

 parallel with the periphery of the cross-section of the shot. 

 Pencils fastened to the prongs of the tuning-fork and vibrating 

 with it are thus made to describe curves indicating the velocity 

 of the ball in its course through the tube. The only objection 

 to the process, which is made perfectly clear by several accom- 

 panying illustrations, is that by the concussion the registering 

 apparatus may get deranged or jammed with the shot. This 

 danger it is proposed to obviate by making the apparatus of the 

 best steel, and diminishing the effect of the concussion by filling 

 the shut with some fluid when fired for experimental purposes. 



In (he last number of the Bolhttino of the Italian Geo- 

 graphical Society, Dr. G. A. Colini continues his valuable 



