SCIENTIFIC NEV^S. 



[May 25, 1888. 



a few standing in sloping and nearly upright positions. 

 On looking around, their source is easily discovered. 

 Here and there are long streaks of barren space in the 

 midst of the wooded slopes. These are due to the fall 

 of vegetable avalanches, to hundreds of trees that have 

 been precipitated into the lake and have floated on its 

 surface until soddened with water, and then have sunk 

 to the bottom. The upright position of the few appears to 

 be due to soil and fragments of rock adhering to their roots. 



At that time I supposed this to be exceptional, but 

 subsequent observations in Norway proved that at the 

 Aachensee we have only a small sample ot what has 

 been taking place on a huge scale in the steep fjords of 

 that country, and which must have occurred far more 

 largely in countries that have had a similar configuration 

 combined with a climate more favourable to vegetation. 



In some of the fjords, notably in the Sognefjord and 

 its upper branches, the Slyngsfjord, the Sunelvsfjord, the 

 Nordalsfjord, and the Geirangerfjord, these vegetable 

 avalanches assume great magnitude, and sometimes in- 

 flict serious calamities by overwhelming farmhouses, in 

 spite of the fact that the sites of such houses are care- 

 fully selected on the best-protected spots, the danger 

 being well understood. The steam-packets that now 

 navigate the above-mentioned fjords aftbrd tourists good 

 opportunity for observing the tracks of such avalanches, 

 which are very plainly and definitely shown. 



Though not visible, as in the curiously transparent water 

 of the Aachensee, it is certain that millions and millions 

 of trees must be lying at the bottom of these fjords, as 

 the tree avalanches must have been continually falling 

 during the whole of the present geological epoch. Their 

 leaves were all rotted before the sinkmg of their trunks, 

 and their potash and other soluble mineral materials 

 washed out during the soddening that preceded their 

 sinking. With a more favourable climate than that of 

 Norway, the quantity would be proportionally greater. 



An iceberg floating into such a fjord would, of course, 

 as it melted deposit any stones, large or small, that it 

 carried, and occasionally some of the trees themselves 

 would carry a stone or two entangled in their roots. I 

 have seen such stones thus bound by the roots of fallen 

 trees that have grown on rocky slopes. 



The quantity of mineral matter in coal thus formed 

 would depend on the turbidity of the water, and would 

 have the composition of the surrounding rocks, as 

 Bischof shows that of coal to have. The fish spines, 

 etc., are equally accounted for, and also the subsequent 

 covering up of the coal seams by stratified rock. Such 

 covering up is now in progress in Norway, where it 

 occurs without any upheavals or depressions, simply by 

 the gradual outward progress of the suspended matter 

 brought down by the rivers which enter every branch of 

 every fjord, and form what the Norwegians csiU oren or 

 sandy delta plains, which gradually and slowly advance 

 further and further into the fjord. 



I do not suppose that every kind of coal is thus 

 formed ; on the contrary, having distilled a few tons of 

 peat, and finding that its hydro-carbons correspond with 

 those obtained from cannel coal and shales, and differ 

 completely from the hydro-carbons of ordinary bituminous 

 coal, I have suggested that the cannel may be an ancient 

 peat deposit in sihi, while the other has been formed in the 

 manner described, by trees corresponding to those 

 found in the strata above the coa/, these latter having 

 fallen at the period when the turbid water was depositing 

 its solid burden which entombed and preserved them. 



DOMESTIC ELECTRIC LIGHTING. 



"\^/'E believe that many people are deterred from 

 • » having electric lights in their houses because 

 they have an exaggerated idea of the first outlay 

 required, and of the trouble and expense of working the 

 apparatus. We are far from saying that there are not 

 often good grounds for such an idea, when the electrical 

 arrangements are made by unskilled persons who have 

 the most imperfect knowledge of what is best, or when 

 electrical contractors try to compensate themselves 

 for the small number of their contracts by charging an 

 excessive profit on each. Fortunately, there are some 

 thoroughly competent electrical engineers who are well 

 versed in the theory as well as in the practice of their 

 art, and among them, as is well known, may be 

 ranked General C. E. Webber, C.B. This gentle- 

 man has made a close study of the simplest and 

 least expensive method of producing electric lights on a 

 small scale for domestic use, and he has lately fitted 

 up his own house, in Egerton Gardens, in a very simple 

 and practical manner. General Webber has been kind 

 enough to let us inspect his house, and has given 

 us particulars of his electrical plant, and of the 

 cost of working it ; and with his permission we 

 have pleasure in making the result known to our 

 readers, as the data given may be thoroughly relied 

 on. 



For the motive power there is a vertical i^ H.P. 

 (nominal) Otto gas-engine of the latest type. This 

 engine drives a small dynamo of the AA2 Victoria 

 Brush type, having an output of about 950 watts. The 

 dynamo charges a battery of 13 L size accumulator 

 cells, such as are shown in Fig. i made by the Electrical 

 Power Storage Company. The whole of this plant is very 

 compactly and conveniently arranged in a cellar under 

 the pavement, the actual ground space required being 

 only 27 feet long by 5 feet wide. The greatest height is 

 only 6| feet. The engine is sufficiently well known not 

 to need a special description, but it may be mentioned 

 that all noise from the exhaust is avoided by letting the 

 products of combustion pass into a pit about 3 feet in 

 diameter by 6 feet deep, filled with broken bricks, and 

 thence up a drain pipe 6 inches in diameter, built in an 

 angle of the wall of the house. A small hand-pump is 

 occasionally used to remove the water derived from the 

 condensed steam which forms part of the products of 

 combustion. As a warning to others we may mention 

 that at first this accumulation of water was overlooked, 

 and it caused such a back pressure in the exhaust that 

 the engine could not be worked properly. As soon as 

 the pump was used there was no further difficulty. The 

 dynamo stands on a brick pier 2 feet 6 inches above 

 the ground, so that all its parts are conveniently acces- 

 sible. The centre of the dynamo shaft is 12 feet from 

 the centre of the engine shaft, and the dynamo is fixed 

 to an adjustable frame, so that the tension on the driving 

 belt can be adjusted as required. The speed of the 

 engine is 160, and of the dynamo 1,550 revolutions per 

 minute. The accumulator cells are placed on insulators 

 in trays of sawdust, arranged in two tiers on a wooden 

 stand, accessible from both sides. These cells are of 

 the new type, in which great improvements have been 

 made in the way of connecting the plates. Also there 

 are no longer any glass plates or rubber bands or plugs, 

 and with ordinary care they need very little attention. 

 The E. M. F. of each cell is not allowed to fall below 2 



