September 17, 1889.] 



Garden and Forest. 



455 



So far, then, the trees in Scotland may he considered to 

 have done as well as those of tiie same age, under good con- 

 ditions, in their native home. Assuming, tlierefore, tliat tiiey 

 will continue to increase as ra[)idly as tlid the great tree whose 

 section was sent to Kew, the conclusion is reached that under 

 a rotation of seventy-live, and i:ierhai)S of eighty, years, the 

 Larch will yield as much solid wood as the Douglas Fir when- 

 ever they are grown in regular, fully stocked woods, and in 

 localities of equal quality — with this dirfcrcnce, that the ma- 

 terial yielded by the Douglas Fir will consist of a smaller num- 

 ber of trees per acre, with a greater mean diameter per tree. 



It may be added that the Douglas Fir would yield a larger 

 amount of wood in a rotation of from 100 to 120 years than it 

 would in a longer or shorter rotation. The difference, how- 

 ever, would not be great, and planters are not inclined to wait 

 so long for returns. 



As to the quality of the tmiber, the wood of the Douglas Fir 

 has a great reputation, and in America its quality is believed 

 to be equal to that of Larch timber. In how far the Douglas 

 Fir grown in Scotland will come up to that standard remains 

 to be seen. The larger sized trees so far cut on the Scone 

 estate have been freely bought at the same rates as those 

 usually paid for Larch, but sufficient time has not elapsed to 

 show the comparative merits of home grown Douglas Fir 

 and Larch timber. 



As to the safety of production, it is an undisputed fact that 

 Douglas Fir can, in Scotland, only be successfully grown in 

 sheltered localities, because its leading shoot, and even the 

 lateral branches, are very liable to be broken by wind. This 

 reduces the area suitable for its cultivation very considerably. 

 Then there can be no doubt that the Douglas Fir, in order to 

 yield large volume retui^ns, requires good, fertile, and fresh, 

 or moist, soil — in fact, soil on which any other species will 

 produce a large volume of timber. Such land can, moreover, 

 be used to greater advantage for field crops. What is spe- 

 cially required is a tree which will do well, or at any rate 

 fairly well, on lands which are not suitable for field crops. 



Finally, it has been said that the Douglas Fir is not exposed 

 to any disease, while the Larch, for instance, suffers so much 

 in this respect. But it will be remembered that the Larch dis- 

 ease did not show itself in Scotland until about sixty years ago. 



No doubt exists now that the Larch cancer is the result of tlie 

 ravages of a fungus, and Dr. von Tubeuf has lately described 

 a similar one which is parasitic on the Douglas Fir. It is 

 found, as a general rule, that those Douglas Firs were espe- 

 cially attacked which grow in fully stocked areas, so that the 

 branches of the trees interlaced ; and in these cases the lower 

 branches were more attacked than those higher up. This 

 means that the Douglas Fir must be grown in thin, open 

 woods, and if so, farewell to any high returns per acre, such 

 as Silver Fir, Larch, or even Scotch Pine, will yield. 



Mr. Schlich concludes by saying that there is encouragement 

 to plant the Douglas Fir in Great Britain and Ireland, and he 

 hopes that experiments may be continued. He only writes to 

 sound a warning against extensive plantatations until it has 

 been demonstrated that it really deserves to supersede species 

 hitherto cultivated. Great things were expected of the White 

 Pine in Great Britain, and probably the Douglas Fir will not 

 revolutionize sylviculture in the United Kingdom. It is one 

 thing to nurse a single tree in a fine soil and under most favor- 

 able conditions, and another to grow trees on a large scale for 

 economic purposes. In the former case only exceptional re- 

 sults are seen ; in the latter case averages must Vje looked for 

 and reckoned with. 



[The result of Mr. Schlich's investigations upon the 

 Douglas Fir in Scotland should be carefully considered by 

 all persons in this country interested in planting, especially 

 by those living in the Northern States east of the Rocky 

 Mountains, where it is believed that this tree may prove 

 valuable in forest-planting. Little is known yet, however, 

 of its behavior in eastern America. The young trees 

 which were planted here first were imported from Europe, 

 where they had been raised from seed gathered in Oregon 

 or California. They proved hardy only in very favorable 

 situations. Dr. C. C. Parry visited the Rocky Mountains 

 of Colorado during the summer of 1862, and found the 

 Pouglas Fir growing there at high elevations. Seeds from 

 these trees were sent by him in the same year to the 

 Botanic Garden in Cambridge (with seeds of Piceapungens, 

 Picea Engehnanni and Piniis Bal/oun'ana, all discovered by 

 Dr. Parry), and a few plants were raised. The largest of 

 these are now more than twenty feet high, and have pro- 



duced cones. A comparatively large number of seedlings 

 have been raised in recent years from Colorado seed, and 

 in one or two places in New England they are being tested 

 now on a considerable scale. The young trees jjromise 

 well, and grow much faster than White Pines planted in 

 similar soil — a light, dry and very porous drift — but not as 

 fast as European Larch. Such experiments, of course, 

 prove nothing yet, except that the Douglas Fir raised from 

 Colortido-grown seed is hardy in New England, while 

 seeds from the same trees, long subjected to the moister 

 and warmer climate of the Pacific coast, do not produce 

 plants which can support the climate of that part of the 

 country. The facts which Mr. Schlich brings out — that the 

 Douglas Fir must have space in order to develop rapidly, 

 and that it requires shelter to protect its comparatively 

 brittle leader and branches — will no doubt prove as true in 

 the United States as in Scotland ; and while enough is not 

 known of this tree to justify any one in believing that it is 

 more valuable than the White Pine or some other native 

 trees, or in planting it in the eastern part of this country 

 upon any large scale, there is enough known to make fur- 

 ther experiments with it in forest-planting very desirable. 

 As an ornamental tree, few hardy Conifers, of course, can 

 equal or surpass the Douglas Fir. — Ed.] 



Correspondence. 

 Storage-Reservoirs for Irrigation. 



To the Editor of Garden and Forest : 



Sir. — I was greatly interested in the article on " Mountain 

 Reservoirs and Irrigation," but, in considering the danger of 

 fatalities from broken dams, it should be remembered that 

 the conditions under which reservoir-construction is to be un- 

 dertaken in the arid region are radically different from those 

 which obtain at the East. Remembering, too, that the average 

 annual rainfall in the arid region is less than twenty inches, 

 and that this is spread over the entire twelve months, it will be 

 seen that the danger from such a tremendous downpour as 

 that which caused the Johnstown disaster is quite remote. 

 Excessive and sudden cases of rainfall are of rare occurrence 

 in California. In that portion of the state in which irrigation is 

 required, the average rainfall docs not exceed twelve inches 

 annually, or one inch a month. Under such circumstances, a 

 dangerous precipitation is well nigh impossible. 



But the builders of the reservoirs now in existence have 

 taken care to guard against any contingency on this account. 

 These reservoirs are never established in watcr-comscs liable 

 to heavy floods. The most expensive affair of the kind in 

 California is the immense reservoir known as Lake Yoscmite, 

 in Merced County. This is fed from the Merced River, a 

 stream familiar to all visitors in the Yosemite Valley. Instead 

 of being formed by the damming of that stream, this reservoir 

 is situated at a distance of several miles from it, occupying a de- 

 pression in the foot-hills. It is supplied with water through a 

 canal 100 feet wide and ten feet in depth, and the flow of 

 water is regulated by a massive and substantial system of 

 head-gates, by which at no time, even when the water in the 

 river is at its highest, can more than is desirable find its way 

 into the reservoir. The lake, as it is called, was formed by the 

 construction of an earth embankment, 4,000 feet long, across 

 the lower side of a depression in the rolling foot-hills. This 

 embankment is 250 feet thick at the base, and tapers gradutiUy 

 until, at the crown, the width is twenty feet. The highest 

 point is some sixty feet above the plain below. The water- 

 face of the embankment is rip-rapped so as to prevent 

 erosion. It is estimated that over 300,000 acres of land can 

 be irrigated from this reservoir, upon which something like 

 two million dollars was expended. 



The most remarkable irrigation storage reservoir in the 

 state is that at Bear Valley, San Bernardino County. This oc- 

 cupies the site of an ancient lake, high in the San Bernardino 

 range of mountains. By some convulsion of nature the moun- 

 tain that walled in one end of the lake was riven, and the water 

 escaped through a narrow and tortuous channel toward the 

 sea. By throwing a dam across this chasm the valley was 

 again filled with water from the winter rains and snows, which 

 was utilized for irrigation in the valley twenty miles away. 

 The only sources of supply are three or four rivulets, too small 

 to be called brooks. There are never any violent storms which 

 might cause the water in the reservoir to rise at such a rate as 

 to be dangerous to the dam, which is a massive arched stone 



