part it performs in the undertaking is essential. While travelling,

Mr. Cooke found great inconvenience to result from the spilling of the acid solution used in Smee’s batteries; and, from this, he was led to consider if the substitution of fine white Shanklin sand, saturated with the diluted acid, would not avoid this difficulty. Experiments having confirmed the truth of his conjecture, the change was permanently arranged, and it was subsequently found so advantageous, that the same method was tried in the permanent batteries, and, in like manner, the result has proved satisfactory. At present, the generator resembles, in its principal features, the one known as Wollaston’s trough; and it is so arranged, that the series of plates of copper and amalgamated zinc, arranged for the evolution of the electric fluid, admit of being placed in a corresponding series of cells, filled with well-washed and dry sand. The _United Service Gazette_ states, that all that is necessary in order to use the instrument is, slightly to moisten the sand with diluted sulphuric acid. The conducting wires are, at their ends, of less diameter, and are so arranged as to form the coiled magnets. Those in the diagram are seen in connexion with the works; the electric current, taking the course indicated by the arrows, occasions the deflection of the needle. The following engraving represents the interior of the machine, and shows the means by which the magnet is connected with the electric current. The parts lettered _a_ are the key-shafts, which, on being turned to the right or left by a handle, pushes one of the springs, _c_, from its point of contact, _d_, and, by changing the course of the electric current, produces a corresponding change in the position of the needle. [Illustration] In making a communication to the person stationed at the point where he wishes the information to be received, the operator, by turning the handle to the right or left, breaks the electric current; then, pressing the wire against pins connected with the battery-poles, the coils of wire receive their full deflective force, and attract the magnetic needles to either side, according to the course of the current. Thus, if the stream of electricity passes into the coil on the right, the upper part of the needle will be attracted towards it; if the stream passes into the coil on the left, then the needle will, in like manner, be attracted to it; thus, giving the whole motion necessary to the pointers. The time which elapses between the moving of the handles and the effect on the pointers, is imperceptible, though we must believe that it really follows it. The dial is divided into five circles, each containing a number of letters, or signs. The left-hand needle moving to the left twice, gives _a_; three times, _b_; once to the right and once to the left, _c_; once to the left and once to the right, _d_; once to the right, _e_; twice, _f_; three times, _g_. The order is then taken up by the right-hand needle moving once to the left for _h_; twice for _i_; three times for _k_; once to the right and once to the left for _l_; once to the left, and once to the right, for _m_; once to the right for _n_; twice for _o_; and three times for _p_. The remaining signs are made by two needles working conjointly, so that the simultaneous movement of the _two_, once to the left, indicates _r_; twice for _s_; three times for _t_; once to the right, and once to the left, for _u_; once to the right for _w_; twice for _x_; and three times for _y_. At the end of every word given, the left-hand needle, moving once to the right, to the cross, indicates that the word is completed. If the receiver understands the word, he signifies it by moving the same pointer twice to the left, and twice to the right, which means _yes_; if the communication is not understood, then the needle points twice to the right, and twice to the left, which indicates _no_. The original word is then repeated; if figures are wanted, the motions for each letter are doubled. Previously to giving a signal, the attention of the operator is called by the ringing of a bell, which is accomplished by an apparatus as simple as it is ingenious.[J] That communications by this means may often be of great importance, is evident, from many newspaper paragraphs. The following appeared in the early part of 1847: “On Friday evening the following message was received at the Chesterfield station: ‘Tell Derby, a Mr. H. has escaped from the York Asylum, and is supposed to have fire-arms about his person. Search all the trains from York. He is tall, has a crooked nose, and has a green coat with pockets at the side. Tell the police to look out.’ To this message another succeeded from Leeds: ‘He is caught at Leeds; they have him quite secure.’” An establishment has lately been opened near the Bank of England, in which telegraphic intelligence may be despatched, or received, in all the principal towns of our country. The difficulties which have existed in reference to sub-marine telegraphs appear to have been overcome; for the time occupied from the commencement of carrying the telegraph across Portsmouth harbour, and transmitting signals, does not occupy a quarter-of-an-hour. The telegraph, which has the appearance of an ordinary rope, is coiled into one of the dockyard boats, one end of it being made fast on shore; and, as the boat is pulled across, the telegraphic rope is gradually paid out over the stern, its superior gravity causing it to sink to the bottom immediately. The telegraph consists of but this line; and, unlike those along the various railways, requires no return wires to perfect the circuit. The electric fluid is transmitted from the batteries in the dockyard, through the submersed insulated wire to the opposite shore; the fluid returning to the negative pole through the water without the aid of any metallic conductor, except a short piece of wire thrown over the dockyard parapet into the water, and connecting it with the batteries. The fact of the water acting as a ready return conductor, is established beyond question. In 1842, Mr. Snow Harris, when proving the efficiency of his lightning-conductors in his experiments from this dockyard to the Orestes, exemplified that water would serve to complete the electric circuit. On that occasion, the distance traversed by the return current through the water was but trifling compared with the space accomplished in the present instance. The batteries used are Smee’s; and a very delicate and accurate galvanic detector, invented by Mr. Hay, the chemical lecturer of the dockyard, has also been brought into requisition. Independent of the simplicity of this sub-marine telegraph, it has an advantage which even the telegraphs on land do not possess--in the event of accident, it can be replaced in ten minutes. At the last meeting of the British Association, the chairman, sir R. H. Inglis, thus adverted to the progress of the electric telegraph, from a report presented to the Legislative Council and Assembly of New Brunswick, relative to a project for constructing a railway, and with it a line of electro-magnetic telegraph, from Halifax to Quebec:-- “The system is daily extending. It was, however, in the United States of America that it was first adopted on a great scale, by professor Morse, in 1844; and it is there that it is now already developed most extensively. Lines for above thirteen hundred miles are in action, and connect those states with Her Majesty’s Canadian provinces; and it is in a course of development so rapid that, in the words of the report of Mr. Wilkinson to my distinguished friend, his excellency sir W. E. Colebrook, the governor of New Brunswick, ‘no schedule of telegraphic lines can now be relied upon for a month in succession, as hundreds of miles may be added in that space of time. So easy an attainment does such a result appear to be, and so lively is the interest felt in its accomplishment, that it is scarcely doubtful that the whole of the populous parts of the United States will, within two or three years, be covered with a net-work, like a spider’s web, suspending its principal threads upon important points, along the sea-board of the Atlantic on one side, and upon similar points along the lake frontier on the other.’ I am indebted to the same report for another fact, which I think the association will regard with equal interest:--‘The confidence in the efficiency of telegraphic communication has now become so established, that the most important commercial transactions daily transpire, by its means, between correspondents several hundred miles apart. Ocular evidence of this was afforded me by a communication a few minutes old between a merchant in Toronto, and his correspondent in New York, distant about six hundred and thirty-two miles.’ I am anxious to call your attention to the advantages which other classes also may experience from this mode of communication, as I find it in the same report:--‘When the Hibernia steamer arrived in Boston, in January, 1847, with the news of the scarcity in Great Britain, Ireland, and other parts of Europe, and with heavy orders for agricultural produce, the farmers in the interior of the states of New York, informed of the state of things by the magnetic telegraph, were thronging the streets of Albany with innumerable team-loads of grain, almost as quickly after the arrival of the steamer at Boston, as the news of that arrival could ordinarily have reached them. I may add that, irrespectively of all its advantages to the general community, the system appears to give already a fair return of interest to the individuals or companies who have invested their capital in its application.’” Professor Morse states, as the result of improvements in this telegraph, the president’s message, entire, on the subject of the war with Mexico, was transmitted with perfect accuracy at the rate of ninety-nine letters per minute. His skilful operators in Washington and Baltimore printed these characters at the rate of ninety-eight, one hundred-and-one, one hundred-and-eleven, and one of them actually printed one hundred-and-seventeen per minute. He must be an expert penman who can write legibly more than one hundred letters per minute; consequently, this mode of communication equals, or nearly equals, the most expeditious mode of recording thought! Here, then, we close our series of illustrations of what is popularly termed “Natural Magic,” but, strictly speaking, of natural laws; having glanced at the arrangements of mechanical skill, terrestrial phenomena, chemical wonders, and the effects of light, heat, and electricity. In doing so, we are reminded of the words of the psalmist:--“Thy faithfulness is unto all generations: thou hast established the earth, and it abideth. They continue this day according to thine ordinances: for all are thy servants,” Psa. cxix. 90, 91. The constancy of nature, thus so clearly indicated, is illustrated by ordinary experience. The child who flies his kite in the air, or places his little ship on the surface of the stream, or gathers together the dry leaves to make a blaze, yea, even by the food that he eats, and by his movements in his daily walks, proves that nature has laws, and that in them there is continuance. In after-life, the fact is still more obvious. Every day and every night bear their explicit testimony to it. Water finds its way to the ocean by a thousand channels; it is raised to the higher regions of the atmosphere to be dispersed in light and fleecy clouds over the four quarters of the globe; and, at length, accomplishes its circuit, by falling in showers on the dry and thirsty ground. “It needs, however,” says Chalmers, “the aid of philosophy to learn how unvarying nature is in all her processes--how even her seeming anomalies can be traced to a law that is inflexible--for what might appear at first to be the caprices of her waywardness, are, in fact, the evolutions of a mechanism that never changes--and that, the more thoroughly she is sifted and put to the test by the interrogations of the curious, the more certainly will they find that she walks by a rule which knows no abatement; and perseveres with obedient foot-step in that even course, from which the eye of strictest scrutiny has never yet detected one hair’s-breadth of deviation. It is no longer doubted by men of science, that every remaining semblance of irregularity in the universe is due, not to the fickleness of nature, but to the ignorance of man--that her most hidden movements are conducted with a uniformity as rigorous as fate--that even the fitful agitations of the weather have their law and principle--that the intensity of every breeze, and the number of drops in every shower, and the formation of every cloud, and all the occurring alternations of storm and sunshine, and the endless shiftings of temperature, and those tremulous varieties of the air which our instruments have enabled us to discover, but have not enabled us to explain--that still, they follow each other by a method of succession, which, though greatly more intricate, is yet as absolute in itself as the order of the seasons, or the mathematical courses of astronomy. This is the impression of every philosophical mind with regard to nature, and it is strengthened by each new accession that is made to science. The more we are acquainted with her, the more are we led to recognise her constancy, and to view her as a mighty, though complicated machine, all whose results are sure, and all whose workings are invariable!” Who is not filled with amazement in contemplating the power of the Almighty? Only let it be his will to set one of his agents loose, and the earth and all that it contains shall be burned up. Well may we tremble at the thought of that “wrath which is revealed from heaven against all ungodliness and unrighteousness of men!” On those who believe not, the curse of Jehovah abides. Would that men considered how fearful a thing it is to fall into the hands of the living God! Convinced by the Holy Spirit of their guilt and danger, they would then fly to the only hope set before them in the gospel. “In vain we seek for peace with God By methods of our own: Jesus, there’s nothing but thy blood Can bring us near the throne. The threatening of thy broken law Impress our souls with dread; If God his sword of vengeance draw, It strikes our spirits dead. But thine illustrious Sacrifice Hath answered these demands; And peace, and pardon, from the skies, Came down by Jesus’ hands.” It has been well remarked by Bacon, that “it is heaven on earth to live in charity, to turn upon the poles of truth, and to rest in Providence.” The tenderness and minuteness of the Divine care are taught us by our Lord himself: “Fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell. Are not two sparrows sold for a farthing? and one of them shall not fall on the ground without your Father. But the very hairs of your head are all numbered. Fear ye not therefore, ye are of more value than many sparrows,” Matt. x. 28–31. Let, then, all who are reconciled to God through the death of his Son, be comforted by this truth. God is not far from every one of us; the vast and the minute are alike under his control; and he has graciously promised that all things shall “work together for good to them that love God, to them who are the called according to his purpose.” In the ignorance and superstition of the human mind, applications are sometimes made to those who are supposed to be endowed with magical powers. Such practices are condemned in the Scriptures as vain and wicked. Hence, says the prophet Isaiah, “When they shall say unto you, Seek unto them that have familiar spirits, and unto wizards that peep, and that mutter: should not a people seek unto their God? for the living to the dead? To the law and to the testimony: if they speak not according to this word, it is because there is no light in them,” Isa. viii. 19, 20.