52 HUMANITY NO GAINER BY THE SAFETY LAMP. THE SPEED-CLOCK. Sir,-Not having seen the speedclock noticed in mechanical any work, you will perhaps indulge me by inserting in your valuable Magazine the following lines: As I have not the satisfaction to know who was the inventor of the speed-clock, I can only say with certainty, that it has been used by the spinners in the West Riding of Yorkshire upwards of twenty years; and I have thought it odd that Donkin's Tychometer should have been so frequently mentioned, whilst the services of its more valuable cotemporary have been passed over in silence. This little machine is constructed by the clock-maker, and may be connected with any part of the works as circumstances admit; but it is generally either propelled from the top of the governor-shaft in the enginehouse, or from the lowest convenient speed inside the mill. It consists of a number of wheels and pinions, so calculated, that when the machinery is running at the most eligible speed, its three hands, which indicate on a dial-plate,hours, minutes, and seconds, correspond and keep time with those of a regular time-keeper, which is always going by its side; so that by comparing these two instruments together it may be easily ascertained at any time of the day what length of thread has been delivered by the front-rollers, or, in other words, what portion of the day's work may be already completed." Though the speed-clock, in its present state, is found to be a very useful appendage to a mill, yet it will be seen that it is still capable of being carried to a greater degree of perfection. It not unfrequently happens in From 1805 to 1816 the manufacturing districts that a gentleman of capital will build a mill, erect an engine, and afterwards let out the power to different individuals in single rooms at a certain rate the spindle per annum, to run so many hours a day, without any thing whatever being said in the contract about the speed or stoppages of any kind. This sort of agreement is sometimes attended with much uneasiness, and with litigation, ending in ruin. Now, by introducing into the speedclock an additional hand to go round once every six months, this cause of uneasiness might be entirely removed, and the speed-clock, like the gasmeter, would then faithfully register every turn of the machinery from one rent-day to another. The parties might specify in their contracts the mean number of revolutions to be gone through each day; and thus secure to themselves a faithful, unbiassed servant, that would not be subject either to the faults or infirmities of human nature. I remain your's respectfully, Keighley. Excess since the introduction of the Davy. The Editor of the Morning Post adds, that he thinks this excess is owing to the workmen relying so much on the Davy, that under its protection they now work in places where they would not have formerly ventured to take a light. We have no doubt this is nearly the true state of the case, and EQUIDISTANT ORDINATE METHOD. 66 was was that had the same hazards only been encountered to which the pitmen were exposed before the introduction of the lamp, there would have been no such excess, but, on the contrary, a vast diminution in the loss of life. We must beg leave, however, to enter our protest against the blame of this excessive dependence on the Davy being thrown on the shoulders of the poor "workmen." It is not the men who work in such places of their own accord, but their rapacious masters, who compel them to work there or starve. In a "Plain Statement of the various Grievances of the Pitmen of the Tyne and Wear," published in 1825, we find one of the principal of these grievances founded on this very circumstance. "When the safety-lamp," say the people of one colliery, introduced, proper allowance made to the workmen for working with it, and no bad aired place was wrought in; but when repeated experiments have proved what the lamp will do, the case is altered; now we have no allowance for the lamp, and the worst and most dangerous places can be wrought. Places are now at work, where the air is so inflammable, that the lamp is frequently red hot; and sometimes it is extinguished, and the danger to the workmen very great in consequence." To the same effect the men of another colliery observe, "Sir Humphrey Davy's invention of the safety-lamp has been an advantage to the coal-owners, but a great injury to the comfort and earnings of the pitmen; for while the former may remain indifferent about the safety of the mine, and neglect to form the proper supply of atmospheric air to the inner parts of the pit on account of the great power of the lamp to resist combustion or explosion, the poor miner has to suffer the most awful agony in an exceedingly high temperature, inimical to his health, comfort, and even life." The manner in which the Davy has been so beneficial to the coal-owners, while it has added to the sufferings of the pitmen, is elsewhere in the same pamphlet explained to be, that besides enabling them to dispense with the old processes of ventilation, it enables them to work a greater extent of ground 53 with fewer shafts, and in both ways to save a great deal of expense. It is truly melancholy to reflect, that an invention which had the saving of life for its sole object, and which, properly used, is so pre-eminently calculated to accomplish that object which brought so much honour to its author, and has been hailed by all the friends of humanity as one of the most precious discoveries of modern times should, in the hands of an over-grasping cupidity be thus employed to the destruction of the very individuals whom it was intended to protect and save! No wonder the poor pitmen should (" between hope and despair," as they say) be forced to exclaim "Poor men suffer, good men grieve, Knaves devise, and fools believe; Help, O Lord! send aid unto us, Or knaves and fools will quite undo us." Surely a patriotic Legislature might be worse employed than in interfering between the colliers and their iron-hearted masters. A state of suffering such as is described in the Statement we have before quoted, cannot long exist in any class, without injury to the interests of the whole community. EQUIDISTANT ORDINATE METHOD SECOND INVESTIGATION. [The following is the additional investigation of this method, which we announced in our 316th No. It will be found similar in its first steps to that of OCF, and to differ from it chiefly in its extension of the equidistant ordinate method, to the quadrature of the circle.-EDIT.] Fig. 1. [B D F Sir-Your correspondent H. T requires an investigation of the rule 54 EQUIDISTANT ORDINATE METHOD. for finding the area of a curvilineal space by means of equidistant ordi nates. Let ABC, fig. 1, be a parabola; AF, BH, CG, three equidistant diameters, cut at right angles by the straight line FGH; through B draw DE, touching the parabola in B, and meeting FA, GC, in D and E. Join AC, then AC is parallel to DE (prop. 11 Parabola.-Woolwich Course) also the area of the parabola ABC is of the circumscribing parallelogram ADEC, (prop. 16, Course.) Now the area AG=(AF+CG) FH, And 2DG (2DF+2EG) FH=4BH•FH. In Fig 2nd. 2 DG+AG=3 DG+DC=3 DG+8 ABD+ +3 BEC 3 AFGCBA..as above, the area AFGCBA (AF+4 BH+CG) FH 3 Secondly. To find an approximation to the area of a curvilineal space different from a parabola. Fig. 3. ...ABCD=(AB+4 P 1+2 R 2+4 S 3+2 N 4+4 15+CD) AP nearly. From which may be deduced the following, 3 (√399+√391+√/375+√351+√/319) 4=382·8367444 2 153 8095068 area of the space ABCD, 3) 573-9667593 191-3222531 From which the area of the circle may be found. For the triangle ADC= 5/300=86-6025405.. 191:3222531-86·6025405=104-7197126 area of the sector ABC; hence 104-7197126+12=785397844=area of a circle, whose 402 diameter is 1. Now the area of a circle whose diameter is 1, is known to be 785398163. If great accuracy is not required, fewer ordinates will answer the purpose. Thus, suppose, AD had been only bisected, the area computed by the above rule will be 191-3003, a near approximation to the space ABCD. I am, Sir, Your's, &c. PERPETUAL MOTION. [The following is an extract from the letter of an esteemed Correspondent, to whom our readers have been indebted for many valuable contributions to our pages.] "I now send you a copy of a memorandum I have placed among a great number of papers, diagrams, notes, &c., on the subject of perpetual motion, but all unintelligible to any one but myself. Infatuation all,' you will say; but though I might not be able to deny this charge in toto, yet this I will say, I can demonstrate the possibility of perpetual motion by the action of material bodies on one another, aided by the constantly existing powers of nature, made available to that purpose. The memorandum is as follows: "Query-What ought to be the reward for the invention of a continual self-acting power which may be increased at pleasure and without limitation, excepting that of the strength of materials acted upon by their own weight? That this is possible and prac ticable I am now convinced, and that there is no law of nature or even theorem in the science of mechanics which G. S. goes to controvert the assertion. But the principles on which it may be effected, and particularly the practical means, have hitherto eluded the researches of the ingenious of all ages to the present hour, and now lie concealed in the breast of an individual who may possibly, from neglect and want of eucouragement, be induced to relinquish a pursuit the developement of which would confer an incalculable benefit on mankind, and the loss of which may require ages yet to come to recover. "That the above is the unequivocal and sincere opinion of the writer is attested by his own hand this 25th of February, 1829. (From the Philadelphia Gazette.) "We were much gratified yesterday, with the result of an examination of a self-moving machine, which may be seen at Bowlsby's Merchants' Hotel, in Slater-street, and which the inventor calls a Perpetual Motion. We have no doubt of its being nearer a perpetual self-moving principle than any invention that has preceded it, and as near as any we shall ever see. The great merit, aside from its practical uses, is its sim 56 MOMENTUM OF FALLING BODIES. plicity, and the certainty and readiness with which you perceive that it covers no trick or deception. It is little less than an illustration of one of the most obvious laws of nature. The agent is the atmosphere, bearing directly, by means of perpendicular boxes and oblique tubes, upon the buckets of a wheel, which is propelled with greater or less velocity, but which is constantly propelled, and will continue to run, without the possibility of cessation, while the materials of which it is composed last, and the present laws of nature continue. The inventor is Mr. Richard Van Dyke, of Orleans county, in this State, who gives it as the result of five or six years' application to the subject. He is a venerable man, communicative and intelligent, and described as highly respectable by several citizens of the West, on whose representations entire reliance may be placed. He affects no mystery, but clearly and satisfactorily explains the arcana of the machine." the Maas, with the intention of making a trial of her powers in the German ocean, before proceeding to the East Indies, and it is not improbable, therefore, that she may favour the Thames with a visit. The great size of this vessel will bring to the recollection of our readers the Columbus, which was built in the river St. Lawrence, in 1824, and made the passage to England in safety, but was afterwards broken up on account of her unmanageable bulk. We shall not be surprised to find that a similar fate awaits the Monster, and for a similar reason. The Columbus was larger than this Dutch rival, by some fifty feet in length, and eighteen in breadth; but not so much so as to constitute any material difference between them. MOMENTUM OF FALLING BODIES. (Continued from p. 425, vol. xi.) A GIGANTIC STEAM-BOAT. The Dutch have been engaged for the last five years in constructing and equipping a steam-boat of extraordinary magnitude, in order to facilitate the communication between Holland and Batavia. It has four masts, is about 250 feet long, has cost upwards of 100,000l., and has been appropriately christened the MONSTER. In consequence of her great length, she hung when going off the slips, and it was some days before she was fairly launched; a circumstance which gave the wits of Paris occasion to remark that their Dutch neighbours were so determined to excel all other nations in the magnitude of their steam-boats, that they had built one so long, that it was several days running off the stocks; a wonder only to be matched by the story of the giant who had so magnificent a stride, that it took three days to sail between his knees. One of the most remarkable features of this enormous vessel is, her extreme narrowness as compared with her length; her greatest breadth of beam being only about 32 feet. Although it is now four years since she was launched, it was not till within the present month that she was ready for sea. On the 7th inst. she descended |