July 20, 1888.] 



SCIENTIFIC NEWS. 



61 



precautions must be taken here, such as tying one handle 

 with string instead of rope, so as to give the dredge an 

 extra chance of freeing itself. The boat is kept just 

 moving, and, when all is ready, over goes the dredge, a 

 few feet of chain being commonly fastened to the rope, 

 not far from the handles, to keep the iron jaws well 

 down upon the bottom. We flop about for half an hour 

 or so in a manner very unpleasant to those who are liable 

 to sea-sickness, or who don't care about the work in 

 hand. Now and then it is well to pull the rope, and feel 

 whether all is right. The grating of the dredge on the 

 bottom is quite perceptible to an experienced hand. At 

 length the word is given to haul in. All hands are called 

 to pull, and slowly, foot by foot, the wet rope climbs to 

 the top. One big heave at the last, and the dredge lies 

 on deck. Often it is absolutely empty; often it is 

 choked with tangle or dead shells, or useless shingle. 

 But the lucky casts make amends for many a failure. 

 The most promising indications are a good number of 

 Echinoderms (starfishes and echini) or broken fragments 

 of pink nullipore. Then the contents are spread out, 

 and the collectors, kneeling on the sloppy deck, rummage 

 for treasures. Pails of salt water, glass plum-jars, tubes 

 of all sizes, and watch-glasses are at hand. Big things 

 are piled up in the pails, delicate creatures which can 

 hardly bear the lightest touch are carefully placed in 

 separate tubes. Meanwhile some thoughtful soul takes 

 compass-bearings of two conspicuous points, so that 

 another trial may be made in the same place. If the 

 weather is tolerable, and the fishing profitable, hour after 

 hour slips by unnoticed. There are fifty things to do, and 

 every moment is precious. At last everybody's strength 

 is worn out. The back refuses to stoop any longer, the 

 knees are bruised, the fingers benumbed. A sailor's 

 meal of boiling-hot tea and biscuits is served out, pipes 

 are lit, and the sense of having enriched one's collections, 

 and laid up happy employment for many a coming 

 winter evening, is a fit reward for all toil and anxiety. 



Like all work that is done at sea, dredging is full of 

 uncertainties. Make no promise as to the hour of re- 

 turn. If you come back empty-handed that is nothing ; 

 but if you have a touch of enthusiasm, and are fond of 

 hard work — if you like a life in which no day is like any 

 other — and if a new animal sends a thrill of delight 

 through your frame, set up a dredge and go to sea as 

 often as you can. 



THE EDISON AND SWAN ELECTRIC 

 LIGHT COMPANY v. HOLLAND. 



A FTER occupying no less than twenty-two days of 

 ■i- ■*- the Court of Chancery, and affording opportunity 

 for the display of the talents of some of the leading 

 members of the bar, a most important patent suit, and 

 one which will be of historical importance, has been 

 decided by Mr. Justice Kay. A case in which the 

 Attorney-General (Sir Richard Webster, Q.C., M.P.), 

 Mr. Aston, Q.C., Mr. Moulton, Q.C., appeared for the 

 plaintiffs, and secured among their witnesses and experts 

 Sir Frederick Bramwell, Dr. J. Hopkinson, Mr. I. 

 Imray, and Professor Dewar, and in which the defend- 

 ants were represented by Sir Horace Davey, Q.C., Mr. 

 Finlay, Q.C., M.P., with the assistance of Professor 

 Crookes, Professor Frankland, Dr. Meymott Tidy, Pro- 

 fessor Silvanus P. Thompson, Professor Perry, besides 

 junior counsel and many other well-known electrical 



engineers, naturally attracted considerable attention both 

 from other barristers and persons interested in the case. 



The Edison and Swan United Electric Light Com- 

 pany sued Mr. W. Holland, the Manager of the 

 Alexandra Palace, for using electric glow lamps 

 which were alleged to be infringements of Edi- 

 son's patent, No. 4,576, of 1879, and of a patent of 

 Sawyer and Mann, taken out in the name of Cheese- 

 borough, a patent agent. Mr. Holland was gua- 

 ranteed against liability by the Jablochkoff Company, 

 who had supplied him with the lamps, and they in turn 

 were guaranteed by the Anglo-American Brush Com- 

 pany, by whom they were manufactured. The Brush 

 Company wei'3, therefore, practically the defendants. 



The Edison specification describes the manufacture or 

 filaments for glow lamps from paper, vegetable fibre, 

 splints of wood, or from a thread rolled from a mixture 

 of lampblack moistened with tar, and " kneaded till it 

 assumes the consistency of thick putty." It is directed 

 that the filaments are to be " carbonised in a closed 

 chamber by subjecting it to a high heat." The claims 

 are: " Firstly, an electric lamp for giving light by incan- 

 descence, consisting of a filament of carbon of high 

 resistance, made as described, and secured to metallic 

 wires as set forth. Secondly, the combination of a car- 

 bon filament within a receiver made entirely of glass, 

 through which the leading wires pass, and from which 

 the air is exhausted, for the purposes set forth. Thirdly, 

 a coiled carbon filament or strip arranged in such a 

 manner that only a portion of the surface of such a car- 

 bon conductor shall radiate light, as set forth. Fourthly, 

 the method herein described of securing the platina 

 contact wires to the carbon filament, and carbonising of 

 the whole in a closed chamber, substantially as set forth." 



In defence it was sought to prove that the patent was 

 anticipated by Mr. Swan, of Newcastle. This gentleman 

 had begun to experiment with carbonised paper strips for 

 the purpose of producing light by incandescence as early 

 as the year 1S45. With a better air pump he repeated his 

 experiments, and in the autumn of 1877 he met Mr. 

 Stearn, who was very skilful in the use of the Sprengel 

 air pump, by which an extremely perfect vacuum can be 

 produced. At a lecture in February, 1879, Mr. Swan 

 exhibited a lamp which was produced in court, and 

 which is well described by the first and second claims 01 

 Edison's patent. Edison was at this time creating a scare 

 with a worthless lamp consisting of a platinum wire, and 

 succeeded in producing a panic in gas shares ; he 

 evidently did not know what Swan and Lane-Fox were 

 doing in this country, and he soon found that a filament 

 of platinum was useless, and turned his attention to 

 carbon. The two English inventors were now on the 

 right track, but had not succeeded in producing a really 

 satisfactory lamp. Swan, though he exhibited very 

 interesting lamps at several lectures, did not appear to 

 think that the combination of a carbon conductor in a 

 vessel wholly of glass, from which the air was exhausted, 

 was sufficiently novel for a patent. In a letter to Mr. 

 Stearn, he said that he had heard that Edison was ex- 

 perimenting with carbon, and he feared that he would 

 forestall him. Invention followed invention so fast, 

 that one method was superseded by another before it 

 could be brought before the public. It is certain that the 

 first Edison lamps that were seen in Europe were at the 

 Paris Electrical Exhibition in 1881. These, however, 

 had fine strips of bamboo, and were made under a 

 subsequent patent. No lamps made according to 



