38 



NA TURE 



[May 8, 1890 



spots. The corona appears to be at least a triple phenomenon 

 made up of — 



(«) The polar rays, seen most prominently about the poles. 



{b) The inner equatorial corona, 'the lower regions of which 

 bear some resemblance to an outer solar atmosphere. 



(c) The outer equatorial corona, consisting of the long 

 streamers for the most part only visible to the naked eye. 



(2) The polar corona consists of rays, straight or nearly so, 

 and radial from neither the sun's centre nor the sun's poles. 

 Rather they seem to radiate from areas the centres of which are 

 adjacent to the sun's poles. 



(3) The inner equatorial corona emits a large percentage of 

 the total light of the corona ; the streamers, however, are not 

 generally so sharply defined as about the poles, and many of 

 them appear to have a real curvature. Four large prominences 

 are visible at about 35° of solar latitude, as if to suggest some 

 connection between the protuberances and the corona. 



(4) The equatorial streamers of the corona are very slightly 

 curved, being convergent on the east side of the sun, and 

 divergent on the west. 



The fact of chief importance established appears to be the 

 periodicity of the outer corona in a cycle probably of equal 

 duration with that of the solar spots. The epoch of greatest 

 extension of the equatorial corona appears to coincide very 

 nearly with the epoch of minimum sun-spots. 



Prof. Todd also directs attention to the most important points 

 requiring elucidation, and throws out a few suggestions for future 

 eclipse observations. 



Brooks's Comet {a 1890). — The following ephemeris has 

 been computed by Dr. Bidschof (^j/r. Nacli., No. 2966), and 

 is in continuation of that previously given (Nature, vol. xli. 

 P- 571):— 



Ephemeris for Berlin Midnight. 



1890. R.A. Decl. Log r. Log ^. Brighl- 



h. m. s. o / ness. 



May 6 ..20 53 21 ...+34 96 ... 0*2874 ••• o'2596 ... 2-60 



10... 46 41 ... 37 44-1 ... 0-2857 ••• 02449 ••• 280 



14... 38 9 ... 41 28-5 ... 0-2843 •■• 0-2314 ... 3-00 



18 .. 27 13 ... 45 202 ... 02832 ... 0-2195 ■ •■ 3'i8 



22... 1*3 16 ... 49 14-9 ... 02824 ■■• 0-2096 ... 3-34 



26... 19 55 28 ... 53 6-2 ... 0-2818 ... 02022 ... 3-47 



30... 32 54 ... 56 46-1 ... 0-2815 ... 0-1976 ... 3-55 



The brightness at discovery (March 21) has been taken as unity. 



Discovery of Minor Planets. — Two more asteroids were 

 discovered by Herr Palisa, at Vienna, on April 25, and observed 

 independently by M. Charlois, at Nice, on the following night. 

 The magnitudes of the planets are 13 and 12 respectively, and 

 their numbers are (^11) and (^\. Prof. Krueger thinks that the 

 latter is probably Scylla {Astr. Nach., 2966). 



THE INSTITUTION OF MECHANICAL 



ENGINEERS. 



A N ordinary general meeting of the Institution of Mechanical 



■^*- Engineers was held on the Thursday and Friday of last 



week ; the President, Mr. J. Tomlinson, in the chair. 



The second meeting of the year is not generally looked on as 

 of great importance, but it is a long time since we remember 

 one of such meagre proportions in one respect as that with 

 which we are now dealing, for there was only one paper on the 

 agenda ; that and the President's address constituted the whole 

 programme. What the proceedings lacked in variety and ampli- 

 tude was, however, fully compensated for in solid value. The 

 one paper, Prof. Kennedy's, is full of valuable information, and 

 Mr. Tomlinson's address came as a most welcome surprise to 

 a good many. In the first place it was short, and, secondly, it 

 was practical — two virtues which appeal strongly to engineers 

 when there is talking to be done ; but beyond that it was one 

 of the most interesting Presidential addresses we have heard for 

 many a day at any of the Engineering Societies. The reason for 

 this is not far to seek. Mr. Tomlinson simply narrated his own 

 experience in plain language, eschewing those ornamental tags 

 of rhetoric which many people look on as essential when they 

 have to speak in public ; and as his experience extends back to 

 a very interesting period of railway engineering, the address 

 proved an exceptionally happy effort. 

 Mr. Tomlinson has been, as he said, a railway man all his 



life ; and, indeed, he has been connected with the engineering 

 departments of more than half a dozen railways, from the Stock- 

 ton and Darlington up to the Metropolitan. His father was 

 passenger superintendent to the former line. His recollection 

 therefore carries him back to the very early days of the loco- 

 motive. His first knowledge extends to the year 1837, when 

 he was employed at the works of Timothy Hackworth, of 

 Shildon. Perhaps no better instance could be given of the 

 simplicity of those Arcadian days than the fact that Hackworth 

 was at once locomotive superintendent and contractor to the 

 railway. Such a dual position might cause invidious remarks 

 on the part of shareholders in the present day. Mr. Tomlinson 

 remembered the three original locomotives placed on the 

 Stockton and Darlington line. One of them, the Locomotive, 

 now stands on a pedestal in front of the North Road Stction at 

 Darlington. The load for this engine was about 22 tons of 

 empty waggons to draw up hill ; whilst down the hill to Middles- 

 borough the waggons loaded, weighing 64 tons, were drawn. 

 The weight of the engine and two tenders loaded was about 15 

 tons. Unfortunately there was no record kept of the consump- 

 tion of fuel, but Mr. Tomlinson used to help put the coal on the 

 tender, and he estimates the quantity to have been 16 to 17 

 cwts, for 48 miles, or about 40 lbs. per engine mile ; but it must 

 be remembered that the gradient was all in favour of the load — 

 in fact, the greater part of the fuel was consumed on the return 

 journey of empty trucks. The cylinders were 10 inches in 

 diameter by 24 inches stroke. The eccentrics had to be changed 

 for back and forward gear by hand, the boiler pressures were 

 30 to 35 lbs. per square inch, and the pistons were packed with 

 a spun-yarn gasket. As the cylinders were vertical there were 

 necessarily no engine springs. There were no brakes, no water- 

 gauge glass, no head or tail lamps, and no whistle. We have 

 not space to follow Mr. Tomlinson in his interesting engineering 

 reminiscences. Perhaps, since Mr. T. R. Crampton has gone, 

 there is only one other engineer living who could give us such 

 unique personal experience of early locomotive days. If so, that 

 engineer is Mr. E. Woods, Past-Piesident of the Institution of 

 Civil Engineers. 



Prof. Alexander Kennedy's paper constituted the second 

 report of the Research Committee appointed by the Council of 

 the Institution to investigate the Marine Engineering question. 

 Within the last few years the Institution has made quite a special 

 feature of these research committees, and we know of no better way 

 in which it could carry out the object of its existence, and, at the 

 same time, keep down the ever-growing financial surplus. The 

 Research Committee on Friction and the Research Committee on 

 Rivetting would have been of great service to engineers if only 

 from the fact that they collected and put in concise form the 

 knowledge already existing on the subjects ; but they did more 

 than this, for they made experiments of their own by which 

 doubtful points were cleared up and new possibilities were 

 suggested. The Marine Engine Committee are following the 

 same useful course under the guidance of their Chairman, Prof. 

 Kennedy, who, it may be remarked, gained his first experience 

 as an engineer in the once celebrated Thames-side marine en- 

 gineering establishment of the Dudgeons. 



As we have said, this is the second report of the Committee, 

 the first, which was read last year, being on the trials of the 

 s.s. Meteor, a London and Edinburgh steamer of 692 registered 

 tons. The vessels since then under trial, and dealt with in 

 the second report, are the Fusi Yama, the Colchester, and the 

 Tartar. The first is an ordinary trading vessel of 214-3 feet 

 long b.p., 29 3 feet beam, 20-5 feet deep, and of 2175 tons dis- 

 placement at trial draught. The trial run was from Gravesend 

 to Portland. The engines are by Samuelson, of Hull, and had 

 just been overhauled. They are of the ordinary two-cylinder 

 compound type. The Colchester is the latest built vessel of the 

 Great Eastern Railway on the Antwerp service. She is 281 

 feet long, 31 feet beam, and 15-2 deep. Her trial displacement 

 was 1675 tons. She is a twin-screw ship, the engines being 

 ordinary two-cylinder compounds. The trial run was from the 

 Humber to Harwich, the engines having been overhauled in the 

 former river. The Tartar was selected as an excellent example 

 of modern economical engines in a cargo-carrying steamer — 

 what is generally known as an "ocean tramp." She is 332 feet 

 long, 38 feet wide, and 27 feet deep. Her displacement tonnage 

 on trial was 2250 tons. She has triple compound engines of 

 the three-crank type. The trial run was from the Thames to 

 Portland. The vessel was light, so that the engines were working 

 at very low power, and, in addition to this, bad weather was met 



