460 



NA TURE 



{Sept. 27. 1877 



by Mr. Starr, a voiinff Ameriran, and patented in this country 

 under the title of " King's Patent Electric Light," specification 

 enrolled March 25, 1846. An account of it, with drawings, 

 may be found in the ATir/ianic's Afa^nziiic, A"ril 25, 1846, 

 p. 312. To this are appended some editorial remarks in which 

 the novelty of the invention was at that date disputed. Those 

 who care to follow the .subject further mav find a letter of mine 

 replying to this editorial criticism in the Mechanic's Magazine of 

 May 9, 1846, p. 348. 



I constructed a large battery and otherwise assisted Mr. Starr 

 in his experiments on this light. The '-wick," as Mr. Munro 

 aptly calls it, was a stick of gas retort carbon, like that pictured 

 (Nature, p. 423I, excepting thnt it was affixed to supports of 

 porcelain in order to remedy the fracture which occurred to our 

 fi^s^ apparatus in which the carbon stick was rigidly held in 

 metallic forceps. Thus the improvement of M. Kosloff was 

 also anticipated. 



The lamp-glass was a thick barometer tube about thirty-six 

 inches long, with its upper end blown out to form a large bulb 

 or expanded chamber. The carbon and its connections were 

 mounted in this with a platinum wire passing through and sealed 

 into the upper closed and expanded end of the tube. 



The whole of the tube was then filled with mercury and 

 inverted in a reservoir, and thus the carbon stick, &'c., were left 

 in a Torricellian vacuum. The current was passed by connect- 

 ing the electrodes of the battery with the mercury (into which a 

 wire from the lower end of the carbon dipped) and with the 

 upper platinum wire respectively. A beautiful steady light was 

 produced accompanied with a very curious result which at the 

 time we could not explain, viz., a fall of the mercury to about 

 half its barometrical height and the formation within the tube of 

 an atmosphere containing carbonic acid. 



I have now little doubt that this was due to the combustion of 

 some of the carbon by means of the oxygen occluded within 

 itself. 



In pointing out this anticipation of M. Lodighin's invention I 

 do not assume or suppose that any piracy has been perpetrated. 

 It is one of those repetitions of the same idea which are of such 

 common occurrence and which cost the re-inventor and his 

 friends a vast amount of trouble and expense that might be saved 

 if they knew what had been done before. 



I may add that the result of our battery experiments was to 

 convince Mr. Starr that a magneto-electric arrangement should 

 be used as the source of pnwer in electric illumination ; and 

 that he died suddenly in Birmingham in 1S46, while constructing 

 a magnetic battery with a new armature which, theoretically, 

 appeared a great improvement on those used at that date. Of 

 its practical merits I am unable to speak. 



Twickenham, September 18 W. Mattieu Williams 



Serpula Parallela 



Two or three years ago I read somewhere that Serpula 

 farallela of M'Coy is probably a vitreous sponge. Can any 

 of your readers give me a reference for this ? I wish to give 

 the authority for this happy suggestion to which Mr. Young and 

 I referred last year. JuHN Young 



Glasgow University, September 19 



HVDROGRAPHIC SURVEY OF THE BALTIC 



"VX/'E learn from the Stockholm Nya Da<rUa;t Allelmnda 

 * * that during the month of July last a hydrographical 

 survey of the lialtic was carried out by two vessels 

 belonging to the Swedish navy, which were placed for 

 this purpore at the disposal of the Swedish Royal Academy 

 of Sciences for a month. A grant of about 550/. is 

 intended to cover the expenses of three such expeditions. 

 The whole of the Baltic, from a line drawn from Arendal 

 to Jutland to the head of the Gulf of Bothnia and from 

 the Swedish coast on the one side to the Finnish, Russian, 

 German, Danish, and Norwegian on the other, was 

 examined for temperature and salinity along thirty-four 

 lines, measuring together more than 23,000 English miles, 

 and including 200 stations. At every such station the 

 temperature and salinity of the sea water were ascertained 

 at the surface and at several different depths down to the 



bottom, about 1,800 different determinations of tem- 

 perature having been made and a corresponding 

 number of samples of water obtained. The nature 

 of the bottom has also been ascertained by instru- 

 tnents which brought up samples not only from the 

 surface of the bottom, but also from a variable depth, 

 occasionally several feet, under it. The plan of this 

 survey, which is said to be the most complete that has 

 yet been made for its special objects, the determination 

 of the salinity and temperature, was drawn up and 

 carried out by Prof. F. L. Ekman. New instruments for 

 taking samples of sea-water at different depths were 

 employed, and as the temperature of t e water did not 

 undergo any perceptible alteration during the time 

 required for getting it to the surface, for every sample 

 that was obtained, the temperature of the depth from 

 which it was raised was ascertained simultaneously, 

 without any great loss of time. The survey shows the 

 Baltic and the Gulf of Bothnia to consist of three strata, 

 differing greatly in temperature, and often very sharply 

 defined, viz., an upper stratum, which is warmed during 

 the summer by the heat of the sun to a pretty high 

 temperature, a lower, in which the cold of winter still 

 prevailed to a great extent, and under the latter still 

 another of a somewhat higher temperature than the 

 intermediate stratum, the third stratum being of great 

 thickness where the depth was considerable. In the 

 Gulf of Bothnia, as in Skagerack and Kattegat, on the 

 other hand, the temperature diminished steadily in pro- 

 portion to the depth, as is commonly the case in the 

 ocean. The uppermost summer-warm stratum of water 

 was found to be of variable thickness at different places 

 in the Baltic ; at some it was scarcely perceptible at the 

 period of observation. This and other peculiarities will 

 probably be explained in the course of the working out of 

 the observations which is now proceeding. 



OUR ASTRONOMICAL COLUMN 



The Saturnian S.'VTELLite HypiiRion. — The fol- 

 lowing ephemeris of this satellite for the next period of 

 absence of moonlight is founded upon the elements 

 calculated by Prof. Asaph Hall, of Washington, from his 

 measures in 1S75. Though limited to dates when Saturn 

 may be observed while the moon is absent, probably her 

 presence, except when very near the planet, is less an 

 impediment to viewing so faint an object than the 

 unavoidable proximity of the planet itself. 



At loh. Greenwich M.T. 



Dist. 

 219-5 

 177-4 

 130-8 

 76-5 

 22-1 



Ah ephemeris of the five inner satellites of Saturn, by 

 Mr. Marth, appears in No. 2,154 of the AstioiwiniscJie 

 Nachrtchten. It is elaborately compiled, but this the first 

 portion, extending to September 20, only reached this 

 country on the date of its expiration. It is to be regretted 

 that a work of this interest involving so much care and 

 trouble in its preparation, should not have been in the 

 hands of astronomers earlier ; it is not the first instance 

 of unfortunate delay in the publication of communications 

 of immediate utility in this periodical of late. 



The New Comet (1877, IV.).— A first approximation 

 to the orbit of the faint comet discovered at Alarseilles on 

 the 14th inst. calculated by Mr. Hind upon M. Coggia's 

 observation on that date, and observations at Leipsic by 



