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of the red line from this point to its junction with the Helensville-Newmarket Railway at Kumeu will be about 18 miles, all of which will have yet to be constructed. There will be one rise of 200 feet, one of 260 feet, and one of 280 feet to be got over, but there will be no tunnel on it. The earthwork on the 3 miles south of the last saddle will be heavy, on the rest moderate. The cost of the bridges over the Kumeu, Ararimu, Waipapakauri, and Waitoki will not much exceed the cost of the bridge over the Kaukapakapa on my first line blue. The drop of about 100 feet on the blue line in the " First Ti-tree Flat" will also be avoided. The height of haulage over the watershed between the Kaukapakapa and the Makarau will be 275 feet above high water on the blue line, and about 325 feet on the red line. The country from the Kumeu to near the Kaukapakapa River on the red line is perhaps the most sterile gum-field country north of Auckland. To the north of the Waipapakauri the country improves rapidly, and includes the Wainui Settlement. The first saddle north of the Kumeu can be avoided by following the yellow line, which, would run in the valley of the Ararimu and Waikookoo, and join the Helensville and Newmarket Railway at the Waimaukau Station. This line would probably be about 2 miles shorter, but all traffic would have to be hauled the distance (3 miles 40 chains) between the Waimaukau Station and the Kumeu Junction. The Waimaukau Station is very inconvenient for a junction. On my first (blue) line, the length of new line to be constructed will be about 11 miles 40 chains from Helensville Wharf to junction with the red line, through country described in a former report (November and December, 1879), but on which, I beg to remind you, there will be a tunnel of at least 12 chains in length. In addition to this 11 miles 40 chains, all traffic will have to be hauled 12 miles 60 chains, the distance between Helensville and Kumeu Junction, or a total of 24 miles 20 chains. I have also examined the country from the Waipapakauri to the road-bridge over the Kaukapakapa near that village, and find that, by keeping on the left bank of the Kaukapakapa Stream, as shown roughly by brown line, an easy and nearly level line can be obtained. This line would do away with the railway-bridge over the Kaukapakapa and the tunnel on the blue line, but would increase the distance by about 3 miles. - The above gives the following results with respect to lengths of new line to be constructed and lengths of haulage on each line to Kumeu Junction. Blue line. —New line to be constructed, 11 miles 40 chains, haulage 24 miles 20 chains. Blue line to Kaukapakapa, then brown line, then red line. —New line to be constructed, 14 miles 40 chains, haulage 27 miles 20 chains. Yellow line to Ararimu, then red line. —New line to be constructed, 16 miles, haulage 19 miles 40 chains ; Red line. —New line to be constructed, 18 miles, haulage 18 miles. If the red line or the yelloiv and red line is adopted, then the piece from Kumeu Junction or from Waimaukau respectively to Helensville will become a branch line. It will thus be seen that each line has its pronounced advantages and disadvantages, and these are so diametrically opposed to each other in each line, that it will require considerable judgment to finally determine on the best line to be adopted, with due regard to engineering, cost of construction, local and through traffic, &c.; and I can at present only recommend that instrumental surveys of all these lines be made before the final decision is arrived at. C. B. Knoepp, Inspecting Engineer.

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