.56 NATURE 



Sjfuly 26, 1877 



Calculating directly for Naples we find : — 



h. m. s. 



Totality began October 12 at 2 18 18 ) Mean time at 



,, ended „ ,, 2 19 28 \ Naples. 



The duration of the total eclipse was im. los., which is in 



satisfactoiy agreement with the words of Kepler. The 



sun was at an altitude of 31°. 



The Binary Star a Centauri.— As far as can be 

 judged from a projection of the measures published to the 

 present time, it appears probable that the nearest real 

 approach of the components in this binary is already 

 passed, but that they will continue to apparently close-in 

 until the angle is somewhere about 110°, when their 

 distance may have diminished to if". We can only 

 continue to urge upon southern observers the great im- 

 portance of frequent measures of this object for sonie 

 years to come, with all the precision that the case will 

 admit of, that a problem of the highest interest in 

 celestial mechanics may be fully investigated. 



MiRA Ceti. — This variable star is now close upon the 

 epoch of minimum, as calculated from Argelander's 

 formula of sines, and observations so far are much 

 fewer in number near this part of the light- curve than 

 about the maximum. The gradual ascent to the next 

 maximum may be favourably watched in the present 

 year ; the date by the formula is November 10, 1877. 



D'Arrest'S Comet. — By M. Coggia's observation at 

 Marseilles on the morning of the loth inst., it appears 

 that M. Leveau's ephemeris gives the position of the 

 comet within about 3'. Subjoined are the calculated 

 places for Paris noon, during the next period of absence 

 of moonlight : — 



August 8 



This comet has not yet been observed under its most 

 favourable situation with respect to the earth. When 

 the perihelion passage occurs early in August, it may 

 approach our globe within 0-3 of the earth's mean dis- 

 tance from the sun, but, so far, has not been seen within 

 a distance of about oS. At the next return at the begin- 

 ning of 18S4, observatirns will probably be difficult, but 

 in 1890, when the perihelion passage (as well as can be 

 foreseen without the calculation of planetary perturba- 

 tions) is likely to fall in the latter part of August or in 

 September, the comet's track in the heavens will be a 

 favourable one. 



NOTES ' 



The annual meeting of the Institution of Mechanical Engineers 

 opened on Tuesday at Bristol. Mr. T. Hawksley, C.E., in his 

 opening address, s.iid it was the duty of the government to adopt 

 such timely measures as would secure to us the paths of the 

 ocean for our food inwards and our manufactures outwards. He 

 deprecated the building of enormous and unwieldy floating 

 castles, and advocated the construction of a fleet of swift, light, 

 well-engined ships, equally capable of sailing or steaming. lie 

 thought the extreme action of some of the working classes the 

 cause of England's trades going ^abroad. There was a conver- 

 sariooe in the evening. 



A REMARKABLE case relating to manufacture and transport 

 of explosives has just been the subject of an inquiry before the 

 Wreck Commissioner. The facts are briefly these : — The pas- 



senger sailing ship Great Queensland left London for Melbourne 

 on the Sth of August last. After the 12th, when she was 

 spoken at sea, she was never seen ; but some wreckage from 

 her was washed ashore the same month on the south coast of 

 England. She had taken on board some thirty-four tons of 

 gunpowder, including two tons of the ' ' Patent Safety Blasting 

 Powder " (a compound made in North Wales by treating wood 

 pulp with acid, and stated to have five times the strength of 

 ordinary gunpowder !). There was also a large quantity of deto- 

 nators and percussion caps. The stowage seems not to have 

 been up to the mark ; still the Commissioner regards it as 

 having been fairly safe, but for the danger of spontaneous 

 ignition of the patent powder, to which the facts appa- 

 rently point as the probable cause of the disaster. The 

 evidence bearing on the manufacture of the compound is 

 not a little surprising. In 1875, the manager in charge of the 

 process was a Mr. Hunt, describing himself as "an engineer, 

 but no chemist:" The powder he turned out seems to have 

 been dangerously impure, and some of it having come into the 

 hands of a Government Inspector was found so bad that a regular 

 visit was made to the Company's works. Eight samples were 

 analysed and pronounced impure and dangerous. Mr. Hunt 

 was displaced. Ilis successor, a Mr. Thistleton, made an 

 attempt, at the directors' request, to re-dip the powder left by 

 Mr. Hunt ; but the smoke became intolerable, and at no deg. 

 the sides smouldered into fire and dirtied everything about, while 

 the heat broke the windows and charred the woodwork. He 

 accordingly suggested that the only way was to dip it in potash 

 solution. The process of remaking was going on in the early 

 months of last year, and it was a portion of this remade impure 

 powder of Mr. Hunt which was shipped on the G/ral Queensland, 

 A few days after she sailed news came of an explosion at the 

 Patent Gunpowder Works, and Major Majendie, having examined 

 a cartridge found on the works after this, wrote that " accident 

 is hardly the term to apply " to what happened. The conclusion 

 of the Wreck Commissioner, then, is that the same event hap- 

 pened at sea and caused the disappearance of the ship. The 

 facts speak for themselves. The case is evidently one of gross 

 mismanagement based on an ignorance which might be laugh- 

 able, though not excusable, in people employed in mixing tea 

 and coffee, but shameful in the direction of a company for 

 making an explosive. Considering the scientific knowledge 

 imperative in making and handling our modern explosives, 

 the appointment of the one manager who was " no chemist," 

 and of the other who was so good a chemist (from the Royal 

 Polytechnic) as to proceed to re-dip Hunt's material tti order to 

 make it stronger, at the request of his directors, and was only 

 warned off when this compound nearly blew him into the 

 air, calls loudly for explanation. It is important that the 

 whole responsibility involved in this disgraceful case be fully 

 elucidated by further inquiry. 



We regret to announce the death of Prof. Adolph Erman, the 

 well-known physicist, which occurred in Berlin, July 13th. He 

 was born in Berlin, 1806, and after'completing a broad range of 

 scientific study, devoted himself to physics, following in the path 

 of his father, who was then professor of that branch in the Berlin 

 University. In 1828 he joined the Norwegian expedition sent 

 out to Siberia to investigate the phenomena of terrestrial mag- 

 netism. His own researches were carried out far beyond the 

 confined limits of' the expedition, and after thoroughly examin- 

 ing the hitherto almost unknown volcanoes of Kamtschatka, he 

 terminated his journey by completing the circuit of the world in 

 a Russian frigate. The rich store of magnetic observations made 

 during the entire tour were gathered together into a work of two 

 volumes. In 1834 Erman was appointed Professor of Physics 

 at Berlin, a post which he continued to occupy up to the time of 

 his death. From 1841-1866. he edited the .^^.r/^/z' fiir wisseu- 



