CONSTRUCTION OE RAILWAYS.

33

D.—No. .Ga.

On however descending the east side of the Tauherenikau Eiver (the main branch breaks in on the west), the hills are very steep, rough, and broken by deep gullies ; and about three miles from where the hills end, a high long slip occurs, about 200 feet in height, and nearly perpendicular, apparently very loose and said to have been made by the great earthquake. A low terrace has formed along its foot, and it appears to be a quarter of a mile long. The whole distance, as the line would go, is from twelve to sixteen miles. The bottom of the valley is a long tortuous gorge, enclosed by high slate cliffs. The slip, with some of the worst features, might or might not be avoided,—this could only be determined by a trial line. In any case, the line over the hills must pass over much country which would return no traffic to the railway. I omitted to state that from where Captain Smith's line crosses the Eimutaka Eange it steadily rises both ways, southwards to the road, and northwards where I followed it until the range joins the snowy mountains of the Tararua, attaining an altitude of 3,200 feot. No saddle occurs throughout the whole length, but several rivers take their rise in it, branches of the Akaterewa and Tauherenikau. I could see the houses in AVellington distinctly. I was led to explore this range because Dr. Hector thought a pass might co-exist with a change of formation, but I regret to say it is not so. Not satisfied with these routes, and receiving a telegram from the Colonial Secretary, relative to a Maori pass by way of Pakuratahi, I next started from the Eimutaka southwards to explore the leading range, and crossed two saddles, each of which is considerably lower than the road; the first, I believe, goes by the name of Lucena's, and which I thought would do, but I was doubtful whether there would be sufficient distance to Featherston to run out the gradient. From a high point I had seen the third lowplace and followed out the range to it. I w ras much suprised by the length of the descent, so much so that I thought I must be going down into the valley; the character of the timber and soil also belonged to a lower level, fern trees growing abundantly. On trying the aneroid I found the saddle to be some 400 feet below the coach road, and so narrow on the top that a cutting of 30 feet would bear expense against length, making the available saddle 430 feet below the road, and leaving plenty of distance to get down to the level of Featherston, where the first station would probably be. The fall to the latter place would be 1,232 feet approximately, and the distance, with a gradient of 1 in 40, nine and onethird miles; the hills also appear not so rough. The fall to overcome to reach Pakuratahi is about 570 feet, and I think, from the look of the country, will not be difficult. After that the river can either be followed out, or a lower part of tho Mangaroa Hill crossed; but I have not examined this part of the country sufficiently as yet to venture an opinion. I can only further say that this line appeared so promising that I have commenced to cut it out to Featherston and Pakuratahi, beginning at the saddle, and going first Featherston-wise, as I consider that the side of greatest difficulty. 1 hope to get done in from two to three weeks, but will write you every week how I progress. Since writing the above 1 have cut three and a half miles down, and have met with very little rock. By Saturday next, if the weather holds fine, I expect to complete the Featherston side. As yet, I have been much delayed by stormy weather. I have, &c, J. Blackett, Esq., Wellington. . John Eochfort.

No. 70. Mr. EocnFOKT to the Hon. W. Gisbohne. Sic,— 'Wellington, Ist December, 1870. I have the honor to report that I have completed the trial line from Featherston to the Hutt Valley, choosing an exit from the bush at Mr. Cruickshank's tunnel, as suggested by Dr. Hector, for reasons which I will refer to presently. Commencing at Featherston the line runs nearly level, working gradually on to the terrace at the rear of Mr. Lucena's house ; this part is open, and without any difficulty worth referring to, and is about two and a half miles. From thence the line will make a slight bond into Mr. Lucena's valley, to preserve the level, and continue on to the low downs, on the south side. Crossing them about one mile from Mr. Lucena's, the gradient changes to about 1 in 43 (the clinometer was set at 1 in 40, but a liberal allowance was made on each observation, which might perhaps decrease the grade to 1 in 45), and winds round the next valley, which has two branches, and then creeps around the several branches of Cross's Valley, until it reaches the saddle with the same constant gradient, excepting the upper parts of the valleys, which are made level to facilitate bridging. The saddle is distant about eleven miles from Lucena's Valley. There are many gullies which will require bridging at the poiuts of crossing, and also spurs, which will have to be cut back or through to form the curves with a minimum radius of 5 chains. On the other hand there is very little rock, and many miles of side-cuttings on hills, with easy slopes and natural ballast. Another favourable feature is the large supply of black birch timber all along the line, available for sleepers, bridges, &c. 1 estimate the height of the saddle to be 1,230 feet above Abbott's at Featherston, without the cutting; but aneroid observations cannot be relied on to within a few feet. I also ascertained the Pass to be 401 feet below the coach road, or, with the cutting, 431 feet. The saddle is narrow, and slate rock is found a foot below the surface at the spot where the tents stood on your visit. Descending the Pakuratahi with the same gradient, the features are somewhat similar to those on the west slope for about a mile down. Here the line crosses another saddle, being part of a spur which divides two branches of the river, obviating the necessity of circumventing a long rough-looking range. This was fortunately crossed without altering the gradient, allowing a small cutting of 7 feet. After this the hills have easier slopes, and about half-way down the line winds round a flat valley, having three branches, one of which lies exactly behind the roadmen's houses ou the Rimutaka Road, 9