of the two different-coloured layers of mud from a depth of 385 feet were submitted to analysis with the following results :

These analyses seem to show that the upper layer contained more organic matter (presumably vegetable matter) and a little more iron than the lower layer. Microscopic analysis of the two layers indicates that the mineral particles were rather more numerous and larger in the top layer, while the clayey matter seemed to be more abundant in the lower layer.

TEMPERATURE OBSERVATIONS.

The serial temperatures taken while sounding out Lochs Ericht and Garry in June 1900 are given in the following table, and those taken in Loch Ericht are shown graphically in the temperature section (Plate III.) accompanying this paper, since they are extremely interesting as illustrating the effect of the wind upon the distribution of temperature.

Loch Ericht.-Like Loch Katrine, Loch Ericht is said never to freeze over, and the surface temperature remains comparatively low throughout

the summer. The surface temperatures taken in Loch Ericht during the visit from 15th to 20th June show a range of 104°, viz., from 46.6° to 57; the higher temperatures were obtained towards the northern end of the loch, and the lower temperatures towards the southern end of the loch. A glance at the temperature section (Plate III.) based upon the observations given in the table shows that the warmer water was all collected towards the upper end of the loch, as the result of a south-easterly wind which blew at times during the six days that were devoted to the survey of the loch, colder water having been drawn up at the opposite end of the loch to supply the place of the warmer surface water driven before the wind.

Loch Garry.-Loch Garry was visited on the 21st June 1900, when the surface temperature was found to vary from 57 at the south-west end to 59-4° at the north-east end, and this would seem to indicate a distribution of temperature similar to that observed in Loch Ericht, but since only one temperature series was taken, it is impossible to form an idea of the distribution of temperature throughout the whole body of

water.

SOME NOTES ON THE BALTIC AND ARCTIC VOYAGES OF THE "ERMACK " IN 1899.

By ARTHUR GULSTON, Superintendent Engineer: Sir W. G. Armstrong, Whitworth, and Co.

ICE-BREAKERS were in existence as far back as the year 1870, the first being a converted tug at Cronstadt; but only in the last decade have they reached large dimensions: such as the railway ferry ice-breaking steamers on the great lakes of America and at the straits of Mackinaw; some built on the Tyne, one of them for Helsingfors in Finland, another for Odessa; ice-breakers at Reval, Riga, Copenhagen, Hamburg, and Vladivostock; and railway ferry ice-breaking steamers for Saratov, and for carrying the trains of the Siberian railroad across Lake Baikal, a distance of 52 miles, where the ice varies from 2 to 3 feet in thickness, and being fresh-water ice, is very tough and hard.

The step from these vessels to the Ermack is a big one. She is the outcome of the fertile brain of Admiral Makaroff, of the Imperial Russian Navy. He had advocated for some years that one or more large ice-breakers be built to keep the ports of Cronstadt and St. Petersburg open all the winter; as, practically up to the advent of the Ermack, these ports were closed by ice for about five months in each year, with consequent loss to commerce, the locking up of the naval arsenals of Cronstadt and St. Petersburg, and the placing of the Baltic fleet in winter quarters. Such a stupendous undertaking naturally caused much discussion and opposition amongst those interested; and especially excitement amongst the inhabitants of Cronstadt, which, being an island, would be

cut off from the mainland by the canal cut by the Ermack, the traffic across the ice to Cronstadt from the mainland being exceptionally heavy. It was also well known that the ice-packs in the Gulf of Finland in some winters were of very large dimensions, and much difficulty was expected in breaking them down, the opponents of the scheme hoping that no ice-breaker could possibly crush through them; and as no certain data had been obtained of the Baltic ice up to the arrival of the Ermack, some little anxiety was felt by those on board as to the results.

Among other means in the earlier stages that Admiral Makaroff adopted to bring his views before his countrymen was the reading of a paper before the Geographical Society of Russia in St. Petersburg on the subject of large ice-breakers. His Majesty the Czar saw a report of this lecture in one of the papers, and spoke to his Minister of Finance, Mr. de Witte, on the subject, telling him to investigate the matter and report to him. The upshot was that a commission was formed for the building of the vessel, and tenders were obtained, with the result that the contract was placed and the vessel built on the Tyne.

The Ermack is 335 feet in length, 71 feet beam, and about 8000 tons displacement, with her coals and stores on board. She was propelled by four sets of triple expansion engines of 2500 indicated horse power each, and has six very large double-ended boilers of 160 lbs. pressure for generating steam. One of the engines was situated in the bow of the vessel, but is now removed to give a better form for icecrushing at the fore-end, as although, the bow engine was useful in Baltic or one-year-old ice, the conditions of the large and harder ice of the Polar regions required a more powerful form of wedge-shape at the bow. The Ermack is capable at half power of putting 1300 tons of weight on the ice to crush it down; this is at her ordinary ice-breaking draught of 22 to 23 feet. The other three engines are placed near the stern of the ship. It is, of course, absolutely necessary that the moving portions of the machinery, the shafts and propellers, should be made enormously strong to withstand the heavy shocks and blows met with in negotiating the ice; and so far the machinery and propellers have withstood the tremendous trials to which they have been subjected. The boilers are clothed all over, and special means are adopted to prevent cold air entering the boiler-rooms and causing sudden contractions on any portions of the boilers. The ship is built of steel, having a complete double skin fore and aft, so that, should the outer shell be pierced by the ice, the ship would float on her inner skin, and, as there are a very large number of compartments, the amount of water let in would be reduced to a minimum; by this form of construction great strength is given to the vessel to resist the shocks when ice-breaking. The bow is enormously strong, and for a considerable distance the frames are only 12 inches apart; the ice-belt in the shell plating is 1 inches thick, and the connection of the plating to the stem-piece is of the strongest description. The ice-belt at the bow portion of the vessel extends to the keel, and at the sides of the ship is 27 feet deep. The angle of the bow is 70 degrees, the sides are at 20 degrees, and the whole ship is built and shaped to withstand ice pressure, whether lateral or vertical.

There are ample means for heating the vessel by steam, also the circulating water, and for keeping the sea inlets clear of ice. The circulating water can also be discharged at the bow or stern to wet and melt the snow, so as to prevent it sticking to the ship and producing great friction. Pumping arrangements were also put in of very large capacity for "heeling" the ship, for "tipping" her fore and aft, and to clear and move her when fast in the ice; and salvage arrangements are fitted to pump out large quantities of water, or to salve another ship in distress. The accommodation is very luxurious when compared with other vessels that have hitherto been to the Polar regions. The ventilation is of the most scientific description, and was found to act admirably in the cold weather. So marvellously is the vessel constructed, that she is practically ice-proof and nearly unsinkable -qualities that give her a vast superiority over any ship which has hitherto navigated the Polar ocean.

The vessel left the Tyne on her maiden voyage for Cronstadt early in March 1899, under the command of Captain Vassilieff, Admiral Makaroff also being on board. On the Sunday week after sailing, the ice blink was seen just before dark came on, and at nine at night the first drift-ice was met off the western end of the harbour of Reval. As a heavy gale was blowing it was thought more prudent to wait until the morning before entering the ice, and it was during this wait that we saw an enormous meteor fall in Finland about 40 miles from us, making night as brilliant as day: portions of this meteor were shown in the Paris exhibition of 1900. I would here explain that out in the Gulf of Finland the small drift-ice is first met; this gradually grows to a paste which in calm weather soon solidifies into floes, which get larger until the solid ice is met, and in this the packs of ice are found. Early on Monday the ship was again steered for the ice, entering the drift about 4.30 A.M., which we continued to pass through until 7.30 A.M., when the field-ice began to be met, and shortly afterwards the ship was ploughing her way steadily through the solid ice. The packs of ice from here to above the island of Sescar were very thick and heavy, with only little water showing in places; and, as much snow had fallen, we had some trouble in getting along, the newly fallen snow being a great hindrance; but when clear of packs of ice the ship travelled at a great speed. That night we proceeded until after ten o'clock, the ice being illuminated by the electric projector, and the sight from the bridge of this illumination was wonderfully fine as the vessel passed through the ice, a dense fog finally bringing us to a standstill. At times the ship would get into a water-lane, and the effect of the ice at the edges of the canal is most interesting. The sea ice in the Baltic is a bright emerald green, and the lines of cleavage of the ice are well seen in the lanes. Of course the vessel gained great speed in these canals, and the smashing of the ice at the end was grand, the vessel driving large masses of ice apart as she tore through them.

The next morning an early start at 4 A.M. was made, and this day was characterised by the large number of packs we had to pass through ; at places the whole face of the ice was a series of packs. The water at