plished possibilities; this is abundantly proved by the success of the telephone in its various forms as an instrument of practical use, which for many purposes threatens to supersede the electric telegraph. Naturally almost, the attention of inventors would be directed to the construction of an instrument by which light might be transmitted by electricity in the same way as the telephone transmits sound. In the spring rumours reached England that such an instrument, under the name of the diaphote or telephote, had actually been invented in America, and it was authoritatively stated that Professor Graham Bell had deposited in the Smithsonian Institution a sealed package, containing the first results obtained with this remarkable invention. When, however, Professor Bell actually made known the instrument which he had invented, it proved to be one for the transmission of sound by the agency of light. The photophone, as his instrument is called, solves this problem in a way which is almost startling in its simplicity. "In fact, it bears the same relation to the telephone that the heliograph does to the telegraph. You speak to a transmitting instrument, which flashes the vibrations along a beam of light to a distant station, where a receiving instrument reconverts the light into audible speech." A plane mirror, formed of thin silvered glass or mica, on which a powerful beam of light is concentrated by a lens, forms the transmitter. Against the back of this flexible mirror the speaker's voice is directed, thus throwing it into a state of vibration; the vibrations are communicated along the beam of reflected light to the receiving instrument at a distant station. This receiver consists essentially of a selenium cell placed in the focus of a parabolic reflector, and brought into communication with the hearer by means of an ordinary telephone; the reflected beam being thrown on this cell, the well-known property of selenium to offer a greater or less resistance to the electric current according as it is more or less acted on by light, causes the vibrations of the reflecting mirror to become translated into audible sound in the telephone. In its present condition it requires a highly practised ear to understand articulate speech transmitted by the photophone. In the experiments which he has hitherto shown in public, Professor Bell makes use of a perforated disc which is made to revolve rapidly and is interposed between the source of light and the selenium cell. The revolution of this disc causes the beam of light to be interrupted at greater or less intervals, and this in the telephone is heard as a musical note. A simple plate of hard rubber placed across the end of a hearing tube is capable of receiving and translating the vibrating beam of light. BIOLOGY. A Fresh-water Jelly-fish.—In the early part of last summer Mr. Sowerby, the secretary of the Botanical Society, observed in the tank of the water-lily house in the Society's garden in Regent's Park a number of floating or swimming organisms, which bore a remarkable resemblance to the medusæ or jelly-fish, so common on our coasts. They had the well-known form of the umbrella, opening and shutting in regular movements, as we see in the jelly-fish in the sea. On submitting specimens of this creature to Professor Lankester and Professor Allman, they were pronounced by those competent naturalists to be really individuals of the true medusa class, the interest attaching to them arising from the fact that hitherto no medusa of any kind has been detected in fresh water. As this medusa was found living in water which is kept at a temperature of from 80° to 90°, it clearly belongs to a tropical species, and was probably introduced into the tank where it was found with the plants of the Victoria Regia. Professor Allman proposes to give this new form of jelly-fish the name of Limnocodium, or lake-bell, to which, in honour of the discoverer, Mr. Lankester adds the specific name of Sowerbii.' Vegetation under the Electric Light.-In March last Dr. C. W. Siemens laid before the Royal Society the results of his experiments on the growth of plants under the electric light, results which serve to show that this light, when of sufficient intensity, has the same action in stimulating the vital functions of vegetable life as the sun itself. With an electric centre of light equal to 1,400 candles placed in his greenhouse at a distance of between 6 and 7 feet from growing plants, he has produced effects on vegetation equal to what ordinary daylight in the early spring of the year is capable of developing. More than that, by alternating the employment of sunlight by day and the electric light during a part of the night, he has maintained a state of illumination equivalent to the nightless days of the arctic regions, and has extracted from the plants double work as it were, so that the marvellous growth during the short summer of the high latitudes has been artificially reproduced. MECHANICS AND ENGINEERING. The Gotthard Tunnel.-For the second time the Alps have been pierced; the Gotthard tunnel, which is to connect the railways that meet at Zürich on the Swiss side of the Alps with those in Italy, of which Milan is the centre, was on the 29th February 1880 pronounced to be an accomplished fact. On that day the mining parties from the two ends of the tunnel met each other, and it was found that the axes of the two parts corresponded within an inch: a triumph of engineering skill, since from the circumstances of the case no vertical shafts could be made to correct the surveying. In its dimensions the Gotthard tunnel has a uniform height of rather more than 9 feet, and in width it varies in different places from a maximum of 26 to a minimum of nearly 25 feet. A new Diving Apparatus.—Mr. Fleuss has invented and introduced an apparatus on an entirely new principle for divers employed in subaqueous operations; it may also be used by firemen who have to enter the suffocating smoke of a burning building, or by a miner who has to encounter the fatal choke-damp. This apparatus consists essentially in a supply of pure oxygen compressed into a small reservoir attached to the diver's helmet. The oxygen can be admitted gradually to mix with the air inside the helmet, while the breath expired by the diver is passed over caustic soda and so deprived of its carbonic acid; all the nitrogen which is left unaffected, together with the remainder of the oxygen not used up in forming the carbonic acid, then returns to the helmet, when having its proper proportion of oxygen restored to it from the reservoir, it becomes an atmosphere fit again for respiration. The reservoir contains a supply of oxygen under a pressure of eight atmospheres to last three hours. 1 Nature, vol. xxii. No. 569, p. 481. PART II. CHRONICLE OF EVENTS IN 1880. JANUARY. 1. Sir Henry Layard, having received no reply to the note presented by him in reference to the measures taken by the Turkish Government against Herr Köller and Ahmed Tewfik, suspended official relations with the Porte. The Embassy, however, maintained semi-official relations with the Ottoman Government, and Sir Henry Layard had an interview with the Sultan. Heavy gales and serious floods reported from various parts of England, especially from the western coast and counties. The principal rivers overflowed and the coasts were strewn with wreckage. From France and Germany similar disasters reported, the Seine, Rhine, and Main having by their overflow occasioned enormous damage. The ratification of the Phylloxera Treaty exchanged at Berlin between the representatives of France, Germany, Austria-Hungary, Switzerland and Portugal. Servia and Luxembourg signified their intention of joining the convention; but from Italy and Spain no adhesion was at the time received. 2. The wreck return for 1879 shows a total of 1,688 vessels, with property valued at 25,500,000l., lost, as compared with 1,594 in the previous year. The British-owned ships were returned at 833-valued, with their cargoes, at 19,230,000l. The registered tonnage of the lost ships amounted in the aggregate to 850,000 tons, including 170 steam-vessels. About 5,000 lives were lost; 425 ships of all flags foundered on the British coast, whilst at sea 150 ships were lost through collisions, and about 40 by fire. 3. The discovery made at Schwerin that funds to the amount of 118,000 marks had been purloined from the Grand Ducal Land Treasury. Defalcations were proved to have extended over many years. The only responsible person, the Landrath von Oertzen Woltow, the leader of the Mecklenburg Schwerin feudal party, died from apoplexy the day after the discovery. A 4. The special congregation of five Cardinals appointed by the Pope to examine the question of the marriage of the hereditary Prince of Monaco and the Lady Mary Hamilton pronounced the marriage invalid, on the ground of absence of free consent on her part, but affirmed the legitimacy of the son, the issue of their marriage. A return issued, showing that since the institution of the order of the Victoria Cross it had been bestowed on 368 officers and men in the naval and military services. Seven who had gained the cross died before it could be conferred, and twenty-seven since they received the honour. Of the 368 members, 171 were commissioned officers, and the remaining 197 non-commissioned officers and privates of both services. At 11 A.M. the inhabitants of Roseau, the capital of the island of Dominica, were suddenly plunged in darkness. At the same time came torrents of milk-white water, mixed with black volcanic sand hail, accompanied by subterranean noises-lasting altogether about fifteen minutes. When daylight was restored, the ground was found to be covered with ashes an inch deep, which were traced to the "Boiling Lake" waters at the southern extremity of the island. During the eruption nearly all the rivers of the island overflowed their banks, and the fish in the Point Mutatie river, which flows from the "Boiling Lake," even those near the estuary, nearly all died. 5. The Tuam News states that for the second time since New Year's Day several persons, including two members of the constabulary force, who happened to pass a chapel at Knock, near Claremorris, after nightfall, had seen an unusual light in the gable of the chapel, and an appearance of the Virgin Mary. The news spread rapidly, and the chapel at once became the object of pilgrimage from the adjoining districts. The break of the ice on the Seine occasioned great excitement and much damage in Paris and the neighbourhood, and the safety of some of the bridges was for a time in doubt. From other parts of France similar accounts arrived. A high wall of ice, or glacier 1,500 yards long, formed at the junction of the Indre and Loire, forced the rapid stream of the former river to overflow its banks. Considerable loss of property in the neighbourhood of Chinar ensued. Efforts were made to blow up the glacier with dynamite, and subsequently an artificial canal was dug by the military. The break-up did not take place until the 10th February, when the ice floated quietly away through the canal. - Charles Shurety, aged 29, executed at Newgate for the murder of a child two years old under circumstances of revolting cruelty. A reprieve, forged by a person who had conscientious objections to capital punishment, entailed two months' imprisonment and 50l. fine on its author. The new Austrian loan of fifteen millions sterling taken up by a syndicate of Austrian, German, French, and Italian bankers at 69.51 per cent., the highest price recorded for an Austrian State Loan. 6. A correspondent of the Journal de Genève, writing from Constantinople, gives an interesting account of the organisation of Abdul Hamid's household, which, he says, he has obtained directly from a high officer of the palace. The Sultan has converted the Yildiz Kiosk, his favourite residence, into a sort of Plessis les Tours, surrounded by thick walls, defended by thirty guns and guarded by a garrison of 3,000 men, and the Turkish court is still the most costly in Europe. The first functionary of the imperial household is the Grand Marshal of the Palace, Osman Pasha, who, besides this office, fills that of Minister of War. Osman's deputy as Grand Marshal is his brother-in-law, Riza Bey, also one of the Sultan's five secretaries. The Sultan has four chief chamberlains, exclusive of several who figure in processions on gala days, carrying the emblems of their office-a bunch of keys-on their backs. Among the latter are the two chief black eunuchs, Bahr Ramoun and Khereddin, who, besides their other titles, enjoy that of "Highness," and are members of the most illustrious orders of the Ottoman Empire. Bahr Ramoun is supposed to favour the pretensions of Russia, while Khereddin is understood to be a warm friend of the English alliance. Twenty-three aidesde-camp are always on duty at the Yildiz Kiosk. Among the other aides-decamp are two renegades and one Christian, General Vitalis Pasha, the organiser of the Roumanian gendarmerie. The renegades are Monsieur von Helle, formerly an attaché of the Austrian Embassy, and M. de Lobell, whose father was at one time an aide-de-camp of King Leopold of Belgium. The former became a Mohammedan spontaneously, the latter at the direct solicitation of the Sultan, who rewarded his complaisance by a lucrative appointment. Five mussahibs, or talkers, are charged with the duty of relieving the tedium of His Majesty's unoccupied moments by lively conversation, by reading aloud, and by retailing in the royal ear the gossip of the capital, with which they are supplied by sixty spies specially told off for this purpose. The Sultan's health is watched over by five physicians, the first of whom is a Greek, Dr. Mavrogeni, a member of the illustrious Phanariote family of that name. The Imperial establishment includes four chaplains, or imaums, and four astrologers. To an officer called the Guidisch Mudiri is assigned the duty of accompanying His Majesty on his walks or excursions. The Mudir is a functionary through whom all orders are conveyed to the working personnel of the palace. Then there are directors of the private apartments, of the Imperial Privy Purse, and of the palace telegraph (the last-named of whom has the assistance of ten employés), five librarians, and a secretary, who receives and reads the not very numerous petitions addressed to the Sultan by his faithful subjects. A buffoon, a company of Turkish singers, a brass band (the leader of which is an Italian, enjoying the rank and emoluments of a Pasha), and five pianists, who have the privilege of giving lessons to the princes and princesses of the Imperial family, complete the hierarchy of the Mabein, or men's department of the Sultan's household. The menial duties of the palace are for the most part performed by women. The sultanas, of whom there are four, and the odalisques, who are reckoned at eighty, are guarded by 120 black eunuchs. Many of the latter are waited on by one or two women servants, and in former times the most highly placed of them lived "as luxuriously as princes." Among the inferior domestic servants of the Sultan there are ten "table masters," who cater for the palace kitchens and see that the Imperial tables are duly supplied with food and properly served. Next come ten maîtres d'hôtel, who superintend the ordering of the menus and the cooking of the meats. The cooks and turnspits who receive their commands number 300, while the services of 200 waiters are required in the different dining-rooms of the Yildiz Kiosk. Besides the inmates of the palace, many persons living in its immediate neighbourhood draw by prescriptive right their daily supplies of food from the Imperial kitchens. It |