The work placed under contract is in most instances in the hands of responsible and efficient men, and has been taken on terms exceedingly favourable to the Company. There is at the present period on the line a force equivalent to 2160 men. The cost of the locks, which are built in the most durable manner of cut sandstone, will not exceed $700 per foot lift, being about thirty per cent. below the ordinary cost elsewhere. The cost of the dams, which are in most instances fourteen feet high, will average about twenty-eight dollars per linear foot across the stream; and the canal, exclusive of locks and dams, generally from $5000 to $5000 per mile. A contract has been entered into for furnishing the remainder of the hydraulic cement; it is found in abundance contiguous to the line; the quality is equal to any I have seen, and the cost extremely moderate. The contract for excavating the tunnel and approaches, has been taken by energetic and persevering contractors on reasonable terms, the former not exceeding the estimated cost: this work is to be completed by May 1887. As much has been stated in relation to the adequacy of the supply of water on the summit, it may be proper to remark, that during the past season I commenced and have continued a series of minute examinations of the most prominent streams relied on for a supply: those examinations have thus far fully corroborated the truth of the statements and calculations embraced in the report made to you last autumn by Mr. Hage and myself. I feel fully satisfied, that with the aid of the reservoirs that can be constructed on the summit, at a moderate cost compared with their utility, a much larger quantity of water may be introduced into the summit and its dependent levels, than will be requisite for the transit of the immense trade that is destined to seek a market through its channel. The reservoirs now under contract will contain as follows: West Fork reservoir, 130,000,000 of cubic feet; area 350 acres: Cold Run reservoir, 88,000,000 of cubic feet; area, 250 acres: in addition to which it is proposed to elevate the banks of the canal so as to retain one foot in depth of available water, and flood several pieces of low ground on its northern or upper side, amounting in all to about 150 acres, which, when full, will furnish about 6,500,000 of cubic feet, making in the aggregate from these sources alone, an available supply of 224,500,000 cubic feet of water, a demand on which may be requisite in a dry season for a period of 100 days. By calculation it will be perceived, that these reservoirs will afford for that period 2,245,000 cubic feet of water per day, equivalent to a discharge of 1559 cubic feet per minute. If to this sum is added the minimum natural flow of water on the summit as reported to you last autumn, (558 cubic feet per minute) it will be observed that the flow of available water in a dry period will amount to 2117 cubic feet per minute, or sufficient, after deducting all that the nature of the soil and climate will require for leakage, filtration and evaporation, for the passage of 185 boats per day. The West Fork and Cold Run reservoirs are about one mile apart: when filled, the surface of the water in each will Occupy the same plane, or be elevated to the same height: it is designed to have a feeder extending from one to the other, so that the surplus water in one can be admitted into the other, if required. A large waste weir is to be constructed on this feeder for the purpose of discharging the waste water when both reservoirs are full. This water, when thus discharged, is conducted into the reservoir on the summit level. The first two mentioned reservoirs will receive the drainage of twenty-four square miles of Country; the summit, the drainage of eighty square miles. The usual depth of rain that falls in this section of country can, I am informed, VOL. XVII.-No. 1.-JANUARY, 1836. 4 with safety be premised at thirty-six inches per annum, or equal to a column of that height, being 83,635,000 cubic feet on a square mile, and on twenty-four square miles 2,107,244,800 cubic feet annually. From experiments made on a large scale elsewhere, for practical purposes, it has been ascertained conclusively, that seventy-five per cent. of the rain that falls can be laid up in reservoirs. From this data it will be observed, that the three reservoirs above alluded to may be filled seven times per year. This exhibit will probably satisfy the most sceptical as to the adequacy of the supply of water. As to the immensity of the trade that will wend its way through the Sandy and Beaver canal to an Eastern market, I believe there has never been surmised a doubt; a glance at the map will prove conclusively that a very large portion of the produce of Michigan, Illinois, Indiana, Kentucky and Ohio, which are rapidly increasing in population and wealth, must be wafted through it. The business of that section of country is now to a great extent accommodated by the New York improvements, but the completion of the Sandy and Beaver canal will secure to it a safer transit to and from the seaboard, much shorter, and navigable six weeks earlier in the spring and three later in the fall than the one now traversed; being sufficient inducements to secure it. What the extent of that trade will be, time alone can develope. On the Erie and Champlain canals, a very large portion of the business done on the first of which is derived from the country above mentioned, there have been received in tolls in 1829 $759,055, 1830 $1,032,476, 1831 $1,194,610, 1832 $1,196,008, 1833 $1,324,521, 1834 $1,292,956, and there is no doubt that the business of this year will greatly exceed the last. On the Ohio canal there was collected in 1832 $82,867, 1833 $136,920, 1834, $151,287, and the amount of tolls received the present year at some of the collectors' offices exhibits an increase of forty-five per cent. over the last. When the canal or rail-road authorized by an act of the legislature of this State at their last session, to be constructed from the western termination of the Sandy and Beaver canal to the Miami canal, near the mouth of the Auglaise river, shall have been completed, it must add an immense revenue to your work, as it, in connection with the Wabash and Erie canal through Indiana, and the contemplated rail-road through Illinois to the Mississippi river, will constitute a continuous chain of internal improvement, extending westerly from the Sandy and Beaver canal 500 miles, and from Philadelphia 1000, into the rich and fertile regions of the west. The following synopsis of the distance the trade of the country situated west and south-west of the Sandy and Beaver canal would have to travel from the western termination of that work, in order to reach a market by the various routes now or about to be, afforded it, will fully justify the conclusion that it must seek a passage through it. Distance by the Ohio Canal, Lake Erie, New York Canal and Hudson River to New York. From the Sandy and Beaver canal to Cleveland From Buffalo to New York 80 miles. 200 66 Distance by the Ohio and Mahoning Canals and Pennsylvania Rail Road to Philadelphia. Distance by the Sandy and Beaver Canal and Pennsylvania Improvements to Philadelphia. From the rapid increase in business on the New York and Ohio canals, it is to be presumed that when the Sandy and Beaver canal shall have been finished, the tolls on the Ohio canal will amount at least to $400,000 per annum; and from the foregoing facts and statements it is to be inferred, that two-thirds of that trade will pass through the Sandy and Beaver canal, which would nett the holders of stock in that work, at the rate charged on the Ohio canal, an income of at least $60,000 the first season.* If to this sum is added the amount that may be anticipated from the liberal grant contained in the amended charter, † which cannot fall short of $150,000, the Company will receive, in the first year after the work is finished, $210,000 in tolls-independent of the large business that may be expected from the country west and north-west of the termination of their workpresenting the novel result of a canal yielding seventeen per cent. on its entire cost the first year after its completion. All of which is respectfully submitted. E. H. GILL, CHIEF ENGINEER S. and B. Canal Co. NEW LISBON, Ohio, Nov. 11, 1835. Physical Science. Of the Tidal Motions of Conductors, free to move. By JNO. W. DRAPER, Christiansville, Mecklenburg, Va. 1. "Dans d'autres circonstances on observe encore au milieu des masses liquides, des mouvemens singuliers qu'il est excessivement difficile The estimate may seem large, but it must be kept in mind that the Sandy and Beaver canal will constitute a connecting link between two large and important works, (the Ohio and Pennsylvania canal improvements) now completed; consequently it has not, like other canals, to await the growth of business. †The amended charter secures to the Sandy and Beaver Canal Co. all the tolls collected on the Ohio canal from boats that have passed through the Sandy and Beaver canal for seven years after its completion. In other cases there occur in liquids, singular motions which are so numerous and changeable as to be very difficult to describe. I shall attempt to give some notion of them, remarking, however, that notwithstanding the many experiments which I have made on the subject, I have not been able to determine any general law respecting them. de décrire, tant ils sort nombreux et changeans. Je vais essayer d'en donner une idée, en remarquant toutefois, qu'après avoir fait de nombreuses expériences sur ce sujet, il m'a été inpossible d'en saisir la loi."(POUILLET.) 2. The singular movements here spoken of by Pouillet, have likewise drawn the attention of several other philosophers. Erman and Serullas have both recorded instances of gyratory motion, produced in certain bodies, especially mercury, by the contact of others. There is also a similar observation, made by some of the earlier chemists, respecting camphor. Strange motions of an analogous description, are also observed in some liquids, under the influence of a voltaic current; these, in the case of mercury, have been particularly studied by Sir J. Herschel, who obtained several remarkable notices respecting them; they are, however, so far as I am informed, as yet without explanation. S. If into a watch-glass, or shallow capsule, as a, a, fifty or sixty grains of mercury is poured, and over that as much water acidulated with sulphuric acid, as is sufficient to cover the surface of the mercury, and the positive and negative wires of a battery of twenty or thirty plates, arranged as indicated in figure 1, the mercury being in contact with the negative pole, and the positive pole being plunged into the water, at a short distance from it, currents are produced, both in the water and in the mercury. Supposing the power of the battery sufficient, the same effect takes place on removing the negative wire out of the mercury, into the water; but if the positive wire is in contact with the mercury, and the negative with the water, there is no motion at all, or at most, the mercury only curls itself up, into an elongated figure. 3 Fig.1. 2 + -+ + 4. This motion varies according to several circumstances, but chiefly the position of the two wires. 1st. If the wires be as in figure 2, or on opposite sides of the mercury, the metal instantaneously elongates as shown by the dots, and currents also are seen playing in the water. 2nd. If the negative wire be introduced into the centre of the metallic globule, and the positive wire be brought on one side, as in figure S, the mercury will bulge out elliptically, at both sides, nearest and furthest from the positive pole -and by regulating the force of the battery, either by changing the number of the plates, or altering the strength of the solution acting on them, the experiment may be so managed, that no motion shall ensue in the mercury, after this elliptical bulging is effected; but now, if the negative wire is cautiously raised from its position, so as to be just out of contact with the surface of the metal, as in figure 4, the mercury is immediately convulsed, and its whole surface covered with a kind of circular waves. On lowering the negative wire to its former position, and advancing the positive, as in figure 5, the moment it comes to the edge of the mercurial ellipsoid, the most intense convulsions are produced, which increase O 4 5 + until contact of the mercury and wire is obtained. 3rd. If the two wires form a kind of triangle with the globule, it turns upon itself. 6 5. At the same time that these movements are going on in the mercury, the surface of the water is ploughed by gentle currents, exactly resembling those produced by a breath from a blowpipe, directed slantingly across the surface, as in figure 6. 6. In proceeding to give an explanation of these motions, I shall not fol low the analytical course of experiment, used in my researches, but commence with those principles, on which a true explanation is founded. 7. It has long been known, that the elements of compound substances, were held together in virtue of an affinity among themselves. Sir H. Davy, Berzelius, and other chemists, were led to suspect that this was due to the electric condition of those elements, and pursuing this hypothesis in its details, several brilliant discoveries were made, which ultimately changed the face of the science. Apart, however, from all hypothetical reasoning, it was found, that the poles of a voltaic battery had the power of influencing the atomic constitution of bodies, so as to be able to hold all chemical combination under control. This remarkable effect was imputed to the electrical attraction and repulsion of the battery-but a battery which is competent to the rapid decomposition of water, and even the reduction of potash, is found to give exceedingly faint traces of any electro-dynamic effect, being unable to cause the divergence of a delicate gold leaf electrometer, or affect the indications of a torsion balance. In the course of certain experiments, I had occasion to notice, that this effect, as to intensity, is entirely regulated by the medium in which the experiment is made; as for instance, a thin lamina of air, or gaseous matter, is nearly a perfect non-conductor to electricity of low intensity, but an expansion of water offers no such resistance. I hoped, therefore, that though I might not be able to exhibit the attraction of a polar wire for a suspended needle in the Coulomb balance, such an effect might ensue, if the experiment was made with the apparatus plunged in another atmosphere, whose conducting power differed from that in which we live. For the conducting power of a medium has no relation either to its cohesion or its chemical properties, and it did not appear improbable, that one might be found, which, though it should not interfere with the freedom of motion of a wire plunged in it, its conducting power, in relation to electricities of very low intensity, might exhibit those effects in a more elevated point of view. 8. To illustrate this reasoning, I took a platina wire, a, c, figure 7, two inches in length, and suspended it by a raw silk thread from a stand b, b, into a vessel filled with acidulated water, as high as d, d. The needle was so arranged, that when it hung with freedom, it was about one-fourth of an inch distant from the extremities of two platina pointed wires, p, n, which |