August 2«, 1876. ] 



JOURNAL OF HORTICULTUEE AND COTTAGE GARDENER. 



175 



WEEKLY CALENDAR. 



OLLA PODRIDA— A CONTINENTAL TOUE.— No. 2. 



LEFT off (page 111) at Aix-les-Bains. It 

 is not my intentioa to inflict your reader.? 

 with a chapter out of Murray, as, if they 

 wish it, they can consult tliat vahiable guide 

 book for themselves. I do not, consequently, 

 wish to enter iuto details with regard to our 

 route, but merely to make a few observa- 

 ^^ y tions which I hope may prove acceptable to 



^ your horticultural readers. 



On the Monday we started from Aix for 

 Turin by the Mont Cenis tunnel. The scenery the whole 

 way is very grand and beautiful, and what is particularly 

 interesting is to note how, as the railway begins to ascend, 

 the character of the foliage and vegetation begins also to 

 change. Ihe rise from Chambery to Modane is vex-y 

 rapid, especially after passing the valley of the Isere and 

 ascending that of the Arc. The mountain sides, espe- 

 cially those to the north and east, are very precipitous, 

 and show the traces everywhere of injury done by sudden 

 thunderstorms washing down the debris of rock, stones, 

 and gravel over the vineyards, which in the lower part 

 of the valleys, nearer to Chambery, are placed on every 

 point of vantage. As one ascends the valley of tlie Arc 

 the vineyards gradually give way to patches of Bye and 

 other corn, the Vines being confined only to the cottages 

 or garden grounds ; but after Mont St. Michael these too 

 cease, though the thrift of the native mountaineers is 

 very manifest in the way in which they turn every bit 

 of ground into use, and Potatoes and Eye are grown 

 wherever there is sufficient soil to form any staple to 

 work on. Thus — though this is to a certain degree anti- 

 cipating matters — I saw on the Swiss side of the St. 

 Gothard Pass after leaving Goschemen a crop of Potatoes 

 in one field grown on the top of three large boulders 

 of rock which had fallen off the cliffs, and which were 

 lying on the surface of the ground, the tops of the stones 

 being about 7 or 8 feet above the level of the field. One 

 thing, however, may be safely remarked as a general 

 rule in all these mountain districts, especially in the 

 valleys down which the i-ivers from the glaciers flow, 

 that the native peasants know full well the value of every 

 square yard of soil, and lose no opportunity of turning it 

 to account. Among other things they are gradually form- 

 ing alluvifil fields in the wider parts of the valley of the 

 Arc by damming up the water, and making it deposit its 

 debris of mud from the glaciers by spreading it equally 

 over the ground by side channels, dams, &c. 



It is interesting to watch this land in process of forma- 

 tion, the lower part of it growing crops of Clover, &c., 

 while the middle can only support marsh plants, as Mari- 

 golds — i.e., Marsh Eanunculus, Iri.^, &c., and the upper 

 part is still a pool of muddy water. All the glacier 

 streams bring down a great quantity of detritus, chiefly 

 of the softer whitish granites or the mountain and mag- 

 nesian limestones. This glacier action seems very con- 

 stant, as in the Isrre, the Are, the Doria, Po, Adige, &c., 

 and the debris which is brought down must be very great ; 

 No 762.— Vol. XXIX., New Seeiss. 



and though it may be perhaps a bold conjecture to 



hazard, I cannot help fancying that the flat alluvial plains 

 of Lombardy have been formed in process of time by the 

 action of the glacier rivers overflowing the plains, carrying 

 their detritus with them. It is certainly very singular to 

 notice the way the plains of Lombardy run quite up to 

 the foot of the Alps. The Alps rising from the plain like 

 cliffs from the sea, not so abruptly perhaps as water- 

 worn cliffs ; but everywhere in Lombardy the plains, which 

 are almost on a dead level without any undulating or 

 rising ground in them, commence immediately at the 

 base of the mountains, and lie like a level sea between 

 one range of mountains to the other from the Alps to the 

 Apennines. 



The line of rails rises up the valley of the Arc about 

 100 feet in each mile till it reaches Modane, when the 

 rise up to the north-west entrance of the Mont Cenis 

 tunnel (3942 feet high) is very rapid. This was, at the 

 time we passed it, the least pleasant part of our journey, 

 as an avalanche had broken in the arched roof of the 

 last gallery previous to entering into the great tunnel ; and 

 while the gallery, or shallow tunnel cut in the side of the 

 hill, was being repaired, the line of rails was carried on a 

 temporary platform of timber and poles, the poles being 

 supported on loose stones on the side of a precipitous 

 cliff overhanging the town of Modane which we had 

 just passed, but which a horseshoe curve of a mile long 

 had brought under our feet again. The train did not go 

 much more than two mOes an hour over this temporary 

 viaduct, and it was a relief to get into the tunnel. 



The tunnel itself is well ventilated, and lighted at 

 intervals with powerful lamps ; the carriages, too, are well 

 lighted ; and instead of the atmosphere being at all op- 

 pressive, as many persons were led to expect when the 

 enterprise of making a tunnel eight miles long through 

 the heart of the Alps was first entertained, it was far 

 clearer and purer than any of the metropolitan under- 

 ground railways. One reason which accounts for this is 

 that there is a gradual ascent from the French to the 

 Italian side till within about a mile of the Italian entrance 

 to the tunnel, so that the column of air which enters on 

 the French side is always inclined to ascend. The height 

 of the south end of the tunnel being 4380 feet above the 

 sea, or higher than the northern by 438 ; moreover, the 

 air at that height is always rarefied, and generally con- 

 tains an excess of ozone. 



As one approached Mont St. Michael on the French 

 side the vegetation rapidly changed, vineyards giving 

 way to Eye grass. Eye grass to alpine plants and short 

 grass ; the sides of the hills where the rocks were not 

 too precipitous being clothed with forests of Fir. Mont 

 St. Michael itself is a very striking and precipitous cliff 

 rising from the valley close to the railway, and being 

 remarkable for the great variety of the curvature and 

 character of the strata, and also for the colouring of the 

 mountain limestone. However, I do not wish to detain 

 your readers with any attempt at any geological descrip- 

 tion of this Mont Cenis range of alpine hill, as the vary- 

 ing character of the strata is most striking. On emerging 



No. HM.-VoL. LIV., Old Eeeies. 



