TRIANGULATION.

A sketch, showing the condition of the principal triangles measured and the extent of the country which they cover in the different counties, is annexed. There are few ill conditioned angles. The region within the limits of the primary lines is covered with a network of inferior angles, which are omitted in this sketch.

Commencing at Crown Point, the angles advanced westward show the means by which geodetic connection has been made with Lake Champlain. A few additional angles should be measured to complete the great quadrilateral and perfect the connection with the lake. Comparatively few of the mountains have been found properly placed upon the existing maps; and it has even been made probable that some of the old county or town lines are improperly located. It has been rumored that the northern boundary of the State-being the boundary between the United States and Canada-is at one point six miles from its true location. These are matters of importance and demand attention. The time is not far distant when a precise triangulation and geographical survey of the whole State will be required.

If, in the course of future surveys in this region, a base line of verification be required, the frozen surface of Long Lake-a true waterlevel-is recommended. Copper bolts, sunk in the rock at the water edge in summer, during the progress of work, would show the exact points sighted to, from the mountain summits-Mts. Seward and Santanoni; and it would then only be necessary to visit the lake when frozen and measure the base. An idea of the feasibility of this operation may be obtained by an examination of the triangulation sketch.

TOPOGRAPHY.

The reconnaissance maps of topography, made during the season, are ninety-eight in number. The mountains visible, and their several peaks, are as properly placed upon them as time and weather permitted; and the extensions of their ridges developed by hori zontal contour lines, afterward filled in with vertical hatchings. The course of numerous streams and rivers, wherever advisable and possible, appear upon these maps, together with many lakes or ponds, whose forms or location required correction. These maps supply the place of plane table work, and will be used in locating the topography upon the large final map.

A specimen of a portion of a reconnaissance map, showing a mountainous region in Warren county, is annexed.

Upon the map-sketch of triangulation will be found a blue line, which indicates approximately the position of the summit of the watershed of the Hudson, or the divide between its sources and the waters which flow to the St. Lawrence river. This is a matter of interest in connection with the canals and general water supply. It may also be of value in the determination of the area of forest which it is necessary to preserve in order to protect from evaporation the springs and streams which are the sources of the Hudson.

CONCLUSION.

The results of the survey are numerous and interesting. The vastness and wildness of the region is the better appreciated when, at this late day, we are able to find within it mountains from 3,000 to 4,000 feet in height, nameless, unascended and unmeasured. The incorrectness of the existing maps is understood, when we discover that the famous Blue Mountain or Mount Emmons is not 4,000 feet high (as represented), and that it is apparently inferior to the lofty neighboring summit known as Snowy Mountain, which rises to an altitude of 3,859 feet, where on the maps is shown a blank.

Again, while geographers have expatiated upon the great elevation (for this region) of the lakes Colden and Avalanche, in Essex county, a little more than 2,700 feet above the sea, they have gone blindly on, unaware that far in the south portion of the woods, the Cedar lakes from whose shores the snows of winter depart slowly-lie, on the great and most elevated plateau of the wilderness, at an elevation of 2,493 feet; not flowing to the St. Lawrence, as represented upon their maps, but to the Hudson river.

As a matter of technical geographical interest, the discovery of the true highest pond-source of the Hudson river is, perhaps, more interesting. Far above the chilly waters of Lake Avalanche, at an elevation of 4,293 feet, is Summit Water, a minute, unpretending tear of the clouds as it were a lonely pool, shivering in the breezes of the mountains, and sending its limpid surplus through Feldspar brook to the Opalescent river, the well-spring of the Hudson.

But I may not enlarge upon these subjects. In the hasty journal of the survey, and in the tabular statements of altitudes taken by mountain barometer, will be found a great number of new results.

Many mountains still remain barometrically unmeasured, though their altitude may be trigonometrically computed. Mt. Dix and Mt. McIntyre, though they have been previously ascended, are among the number unmeasured. The appropriateness of the new names

Mt. Redfield, Mt. Street and Mt. Adams given to summits hitherto unnamed, will be appreciated by those acquainted with the written history of the region.

It is now a question of political importance whether the section covered by this survey should not be preserved, in its present primitive condition, as a forest-farm and source of timber supply for our buildings and our ships. The deprivation of a State of its timber is a grave error in political economy, and at this time when the western States of the Union, feeling their deficiency, are laboriously planting forests, it behooves us to see to the preservation of those with which we are spontaneously blessed.

The question of water supply, also, is intimately connected with this proposition. I have elsewhere expressed my opinion that within one hundred years the cold, healthful, living waters of the wilderness-the home of the brook trout, a fish that cannot exist in an impure streamwill be required for the domestic water supply of the cities of the Hudson River valley. With the exception of the Croton watershed, which, however, has its limits of supply, almost all the available water falling into the Hudson below Albany is the surface drainage of a settled and well farmed region, inferior in quality, often charged with the deleterious products of paper-mills and factories; being, in short, from watersheds over which the public has no control. It is not possible to protect from defilement the waters flowing through a settled country. Every storm washes the fields and carries to the streams, in solution, the strength of the manures of the agriculturist and muchdissolved mineral matter derived from the plowed soil of the fields. The trees also are cut away to the water's edge, and the shallow streams, lacking the volume and depth, which, in great rivers, renders the exposure of the surface of the water to the sun a mere superficial and immaterial matter, now, heated and evaporating, become nauseous and slimy with a growth of decaying vegetable organisms. The streams of the wilderness, on the contrary, are sheltered from the sun the thick overhanging foliage of the forest. The more extensive underlying rocks of the region being generally gneissoid, contain little soluble matter; and the pure water from the clouds, after gaining carbonic acid by exposure to the air in the breezy lakes, comes brightly foaming over many a picturesque rapid and waterfall to the Hudson and the sea. A stone dam thrown across the Hudson above its junction with the Schroon, while securing water free from deleterious substances, would afford the head of water necessary for aqueduct purposes; the superfluous waters of the river escaping at the center

of the dam, through a flume, would be sufficient for the purposes of the lumberman or the "river driver." The Sacondaga river above Northville is pure and of great value, and could be treated in the

same manner.

The great expense attending this project is the aqueduct, which, if extended to New York city, would be more than 200 miles in length. When we consider, however, the Roman aqueducts (the Aqua Marcia, sixty miles in length, built 145 years before Christ, and the numerous other aqueducts, some of which are in use to this day; the aqueduct of the inferior town, Civita Vecchia, twenty-three miles in length; in Provence, that which supplied Nismes, crossing deep valleys at a height of 188 feet, conducting the water for a distance of twenty-five miles), the aqueduct proposed will not appear chimerical.

In Scotland, the city of Glasgow is supplied with water brought from Loch Katrine, distant twenty-six miles; furnishing 19,000,000 gallons a day. This aqueduct was completed in 1858.

In France, a covered conduit, eighty miles in length, conveys to Paris 8,000,000 gallons of pure spring water, daily, from the head of the Dhuis, in Champagne; and progress is being made upon the Vanne aqueduct, 104 miles in length; estimated to yield 22,000,000 gallons a day.

In England, the water furnished London being inferior in quality, a new source of supply, from the head waters of the River Severn in North Wales, distant 173 miles, has been suggested. The cost of the aqueduct is estimated at about $43,000,000.

All these works are undertaken for the sake of procuring pure water, for, though each of the cities above mentioned has a river flowing past it, from which water could be obtained by steam pumps, the people of those cities are not satisfied, and demand such a pure supply as will secure them from cholera and other epidemics.

If the present ratio of increase of population continues, the Hudson River valley must eventually contain one long, marginal city, extending from the Mohawk river to New York. The Adirondack Wilderness is the only watershed which will afford a sufficient supply of pure water for such a population as will then exist.

In this country the Croton aqueduct, thirty-eight miles in length, has shown the practicability and value of this method of supply. Allowing that 150 miles of the proposed Adirondack aqueduct be built at the expense of the cities of New York and Brooklyn, and fifty miles at the expense of Albany and Troy, we have the major portion

of the work complete; while ten other towns, each worthy of an aqueduct ten miles in length, would render their aid to the enterprise. Although this source of water-supply cannot, for various reasons, be made immediately available, yet, unless action be taken at this time, and the forests protecting and purifying the waters be themselves protected, there will be no opportunity in the future to accomplish this great work.

Such vast enterprises are of slow progress. If this aqueduct were commenced in these days, long before its completion the failing water supply, would rouse the people to a clamorous demand that it be finished. For the present, the protection of the forest is all that is required, and unless this be done we shall incur the merited scorn of posterity.

In consideration of the hardships and exposure experienced in this exploration, it may be proper to remark that not a particle of alcoholic or fermented liquor of any kind-even for medicinal purposeswas used, carried or permitted to be used or carried by any member of the party. It was a rule against which some of the men employed murmured, but they were only able to break it surreptitiously. The result has been subordination, steady work, health and success.

The survey has now progressed far toward completion. The measurement of additional angles, with some other work, is contemplated during the coming season. Accompanying the report will be found the map, sketches of primary triangulation and reconnaissance, therein referred to.

All of which is respectfully submitted.

VERPLANCK COLVIN.

ALBANY, March 10th, 1873.