Scientific American Supplement, No. 455, September 20, 1884

he charge current

ion after 200 hours' for

ERNING CO

the 4 positive electr

the 3 negative elec

itive electrodes.

ative electrodes.

e trough. 2.

e liquid. 4.

attachments. 0

al. 17.16 k

ry indicates that a zinc accumulator might store up as much as 15,600 kilogrammeters per kilogramme. If the present mode

er accumulator constructed in France. The new model possesses, then, despite the size of the positives and the box,

gulating voltameters in lighting by incandescence, for deadening piston strokes, attenuati

OF A LIGHT

. SL

understorms, accompanied, as they have been, by vivid lightning discharges of a more or less hurtful nature. The list of disasters publishe

d are rather whence comes the electricity, and in what way is the thunderstorm brought about. In attempting to answer these questions, sight must not be lost of the f

h as air is one of the very best insulators, this difference of condition (or potential) in any particular region is in most cases incapable of being neutralized or equilibrated by an electric flow. Consequently the air remains more or less continually charged. With these points admitted as facts, the question arises, Whence this electricity? There have been very many and various opinions expressed as to the cause of terrestrial electricity, but far the greater portion of such theories lack fundamental probability, and indicate causes which cannot be regarded as sufficiently extensive or operative to produce such tremendous effects as are occasionally witnessed. I take it that we may safely regard the evolution of electricity as one of the ways in which force exhibits itself, that, in other words, when work is performed electricity may result. When two bodies are rubbed together, electricity is produced,

ow comes it that the air is also charged, and with electricity of greater tension than that of the earth itself? It was pointed out by Sir W. Grove that if the extremities of a piece of platinum wire be placed in a candle flame, one at the bottom and the other near the top, an electric current will flow through the wire, indicating the presence of electricity. If an electrifi

may be, of the earth's electric charge. This small charge distributes itself over the surface of the aqueous particle, and the vapor rises higher and higher until it reaches that point above which the air is too rare to support it. It then flows away laterally, and as it approaches colder regions gets denser, sinking lower and nearer to the earth's

elling itself" to the utmost limits of any conductor upon which it may be confined. This will account for the charge finding its way to the surface of the water particles, and will furthermore account

ensity implies increased weight, and the cloud particles, as they sail poleward, descend toward the surface of the earth. Assuming that a spherical form is maintained throughout, the condensation of a number of particles implies a considerable reduction of surface. Thus, the contents of two spheres vary as the cubes of their radii, or eight (the cube of 2) drops on combining will form a drop twice the radius of one

face electricity of the opposite kind. Thus, assuming the cloud to be charged with positive electricity, the subjacent earth will be in the negative state. The two electricities[3] exert a strong tendency to combine or to produce neutrality, whence there is a species of stress applied to the intervening air. Possibly the cloud

stance of the intervening air; and if this resistance should prove too weak, what happens? How does the discharge show itself? It takes place in the

trols the discharge? Does the quality of the charge?-that is to say, is the positive or the negative more prone to break disruptively through the insulating medium? Investigations with Geissler's and other tubes containing highly rarefied gases have made it tolerably clear that there is a greater "tearing away" influence at the negative than at the positive pole, and if two equal balls, containing one a positive and the other a negative charge, be equally heated, the negative is more readily dissipated than the positive. But, so far as we at present know, this question enters into the discussion scarcely, if at all. Ou

ar (or positive) state is also produced at some place more or less distant. Sometimes this "freed" positive (which, by the way, accumulates gradually and physiologically imperceptibly) is collected at some portion of the earth's surface. When the negative is neutralized by the discharge, the fre

pelled. It is noticeable that the needle of a galvanometer, starting from the middle position, goes gradually over to one side, eventually indicating a considerable deflection. Suddenly, owing apparently to a lightning discharge some distance away, the force which caused the deflection is withdrawn, and the needle

lausible reason for declining to regard any other large conducting mass in a similar light, and as a body capable of being subjected more or less completely to the various impulses affecting the earth. In other words, a large ma

the room, and out of the door, or up the chimney, is all moonshine, and before dealing with lightning protectors I intend to expose some of the fallacies concerning lightning. Were the discharge to pass through a house, it would infallibly leave more decided traces and do more damage than simply scaring a superstitious old lady now and again. Many people are often and unnecessarily frightened

3

or the double "fluid" theory. Whether electricity be of two kinds or no, the fact remains that there are two condit

ES ON MA

. DU

e batteries the plates are directly in contact, and in others they were separated by leaves of pasteboard, the thickness of which varied from that of the thinnest paper to 0.001 meter. The batteries were placed in the central portion of a very powerful magnetic field, and after they have been taken out they formed perfectly regular permanent magnets. The supporting power of these magnets was the greater the nearer its constituent plates were to each other. In a battery of 100 plates, touching each other directly, and strongly pressed into a brass cylinder, the portative force

thallium is exactly the mean of the thermic constants of potassium and

GAS LIG

IGHT

aced 2? inch apart center to center. The keel and stem are both in one piece, as shown, and to this the garboard strake is to be fastened. The bilge pieces are riveted on to the bilge, and made of 9 inches by 4? inches by 9/16 inch T-iron. A wooden fender, 4 inches by 4 inches wood, is fitted on both sides of hull, running from stern to stern, by 3 inches by 3? inches by 7/16 inch L-iron top and bottom with the sheer as shown. The hull from water line falls in as shown, so as to describe at midships an arc of 4 feet 6 inches, and a circular deck of ? inch plate is riveted on the hull. There are two man-holes, each 16 inches diameter in the clear, placed in end plates of the circular deck as shown, and provided with covers ? inch thick, secured by twenty screws ? inch diameter. The edge of each manhole is stiffene

IGHT

A ROADSTEA

s with the rapidity required by our epoch. So they are gradually abandoning our port, and going to load and unload at Anvers and elsewhere. A large number of wise heads, who are anxious about the future of this port and our national int

HE PROJECTED ROA

one side by the heights of Heve and St. Adresse, and upon the other by the rocky line of Eclat and of the heights of the roadstead (Fig. 1). This Little Roadstead, so called, in orde

onstructing upon the Eclat reef a semi-lunate dike, and a breakwater at Cape Heve. Moreover, upon

IS' FLOATIN

ection of a fort upon the Eclat, and requests have periodically been made and projects drawn. The requests are forgotten, but the drawings are in the Minister

as to be placed a floating breakwater. This project, which was submitted to Admiral de Hell in 1845, had a favorable reception, and the Admiral especially applauded the trial of breakwaters, "which were much talked of in England, although the effects that they might produce were not well known." Deloffre, Bleve, and Renauds' project com

LE'S FLOATING BRE

pon the eminences of the roadstead. These would be constructed by forming a foundation of loose rocks, and using earth and brick above the level of the water. Mr. Vi

the construction of a dike about 2,000 meters in length, starting from the Havre jetty, and ending at the southwest extremity of the shoals at the roadstead heights, and a se

of the current, which, throwing back at the ocean its mud and pebbles, would g

sen; one of them due to Mr. Thuillard-F

ite the entrance to the port at 1,600 meters from the jetties. Through it there would be five passages. Afterward another dike would be constructed, starting from the shore and running to meet the jetty designe

ose that have been proposed, has one fault, and that is that it

to inclose the Havre roadstead by means of floating breakwaters. As we have already seen, the use of these between Cape Heve a

rm anchored in a singular manner, and surmounted by rooms for watchmen, semaphores, posts for the shi

d to cut the waves and cause them to break over it (Fig. 2). If, by favor of divine Providence, this breakwater, which presents absolutely plane surfaces to the shock and pressure of the waves, is not broken to fragments in the first tempest, it will certainly acquit

S BREAKWATER.-MODE O

eams that form the angles of the prism. To these beams are affixed the cross pieces that form the openwork sides. Five long pieces of wood parallel with the beams, but not so strong as they, protect the cross pieces and secure them against breakage in the middle. All the angles of the breakwater and all points of juncture of the pieces are protected with iron, and it is in order to counterbalance the w

oscillate. Between these two bars there is a sort of swivel, whose pieces, in playing upon one another, give the breakwaters elasticity, while always holding them apart (Fig. 4). From each side of the swivel start the branches of a stirrup iron to which t

ing at the north from Cape Heve, taking in depths of 15 meters (the best that are found in the Little Roadste

s, and the second for lending its aid in times of high tempe

its promoter to affirm that in a few months, and wi

in bad weather. In addition, a system of lighters, or, better, a few floats connected with th

ers and protecting the advances of torpedo boats by means of their firing, would make a formidable defense. Not having to perform any evolutions, they might without danger be invested with armo

oning, and yet, for defending the very original system proposed by Mr. Froideville, we have only our conviction, which we share, moreover, with a large number of sea-faring men and engineers. Mathematics are powerless to predict to us with accuracy the manner in which the floating

D CATCH

rge foreign cities. There may be found there a description of the Liernur system at Amsterda

D CATCH

of sewers of small section, provided that it shall be unnecessary to enter them for the purpose of cleansing them. It has been necessary, therefore, to provide inlets with a separating apparatus called "gully" or "catch basin," which retains as completely as possi

of perforated sheet iron, which occupies almost the upper half of the device and rests upon the smaller lower part. The entire apparatus is covered by a movable funnel, through which enter water and any ru

sheet iron rushes in a filtered condition through the annular space which exists in the upper part between the two cylinders, and escapes by the waste-pipe when the water reaches a proper level. If at a given moment the quantity of water flowing in is too much to be discharged through this waste-pipe, the level of the water mounts in the cylinder until it reaches t

y floating matters. When siphonic action ceases, the water in the short arm of the siphon empties itself into the main receptacle, and by so doing cleanses the screen. During a rain or the washing of the street

the ordinary type, where the grade is small or where the quantity of water is insufficient; and if we adopt the system of "everything to the sewer," can we not

SUPPLEMENT No.

H PRESSURES AND WROU

MITH, JR., M.

TING WATER AND TR

ing, in readiness for such an emergency. A pipe main was laid along the general line of the tunnel, with its pen-stock 285 feet vertical above the surface at the upper shaft, and 549 feet above the lowest shaft. It was made of single riveted sheet-iron, of No. 14 (Birmingham) gauge, in lengths of 20 feet, put together stove-pipe fashion, with the joints made tight by cloth tarred strips and pine wedges. This pipe had a diameter of 15 inches at the pen-stock, diminishing from this to 13, 11, and 7 inches at its lower end. From it, short branches, 7 inches in diameter, were extended to the several shafts. It was in one place carried across the stream by a light suspension bridge, some 150 feet long, the trunk of a tree on each side forming a convenient tower. The aggregate length of the main and branches was 9,960 feet,

G.

ped. At the end of this discharge-pipe was a cast tapered nozzle, about 3? inches in diameter, in which was inserted a ring of saw-plate steel having the desired diameter, and which was held in place by an annular screw-cap. By changing the ring, which only required a few moments' time, any desired amount of water, up to 3 or 4 cubic feet a second, could be discharged against the wheel. The stop-gate was left wide open while the machinery was running. The pumping was done by eighteen pumps, of Cornish pattern; the largest amount of water pumped from any one shaft was something over 30 cubic feet a minute; the power at hand, however, was ample to pump more than twice that quantity. It was rather curious at, this shaft to see more water coming from the pumps than was used on the wheel. The two diamond drills were driven by a small hurdy-gurdy set on the rear of the drill carriage. This, but at another tunnel, was afterward modified by placing a separ

G.

ated by placing each joint in a bath of boiling tar and asphaltum; to insure the most thorough coating, it is necessary to keep the pipe for ten or fifteen minutes in the boiling mixture. A cast-iron stop-gate is placed at the lower end of the main, and also one at each of the branches. Cast-iron man-holes are attached to the main, which, although they have given no trouble in this particular case, are v

eet. For power and for mill uses, etc., the required supply is about 8 cu

in driving the follow

ouble acting, air compressed to 75 po

vertical; 12-inch plungers for upper 800 feet, 6-inch plungers for l

wo connected winding reels, moving separat

s and smithy forges, req

trating apparatus, etc., req

g say 320 horse-power, for which seven

the sheaves or pulleys are slightly oval, so that the rope does not go quite to the bottom; the ropes are horizontal, and

G.

t, at the Idaho, to be greatly preferable to the gearing formerly in use when the works were driven by steam (for s

5] per minute, with 1-15/18-inch nozzle; three ropes are used from the wheel s

inute. There are two ropes from the wheel-shaft to a counter-shaft, and four ropes to the fly-wheel shaft, on which is the pinion driving the spur-wheel attached to the pitman of the pump-bob. Hoisting is done by two wheels placed side by side on the same shaft, the buckets and nozzle of each wheel being placed in opposite directions. Both wheels are 8 feet in diameter, with 15/16-inch nozzles, and make at full spe

of water at this point is a few feet greater than at the other wheels. Power is transmitted from the hoisting and mill-wheel shafts by two and four ropes, the same as with the pumping rig. The amount of work done, or of water used, has not been carefully determined; judging from the indicator cards taken from the old steam-engines, the managers of the Idaho believe that an efficiency of fully 80 per cent. of the theoretic power of the water is obtained on the main driving-shafts of the machinery

4

y, as the elasticity of the iron will admit of the movement

5

as here given, are only approximate, as the

K PIPE AND

t, which was located on the side of Big Ca?on Creek, at a vertical elevation of 620 feet above the bed of the latter stream. The quantity of water to be carried was about 32 cubic feet a second (1,250 miner's inches), which could be diverted from Texas Creek at a point 480 feet vertical above the Bloomfield flume. An aqueduct about 4,000 feet long, partly of ditch and partly of flume, was needed to bring the wat

et. The head fixed upon was 303.6 feet, with a length of 4,438.7 feet. A profile of the pipe, with nearly the same horizontal and vertical scales (horizontal scale, showing slope

feet, 0.083

" 0.

" 0.

" 0.

" 0.

" 0.

" 0.

ntil too late to have it corrected. Since then, the writer has always had such pipes-the mines of which he has been the manager using large quantities-made directly on the ground where they are to be used; the pipe makers, in the latter

G.

s was soon remedied by more careful calking. No man-holes or escape-gates were used. The pipe for the larger part of the year is not filled at its upper end; when such is the case, the water at the inlet carries down the pipe a great quantity of air, for which escapes must be provided to prevent a jarring or throbbing, which would soon destroy the pipe. The escape air-valves used are shown by Fig. 16. They consist simply of a heavy flap valve of cast-iron, with recess for lead filling to give greater weight set on top the pipe, seating on a vulcanized rubber cushion, and swinging on a loose hinge. When the pipe is only partly filled with water, the valves drop down by their own weight, allowing the air to freely escape; when the water rises above the level of a valve, it is tightly closed by the resulting pressure. There are fourteen of these valves, those on the lower end being designed to allow air to freely enter the pipe in case it shou

on the bottom of 3 feet, on the top of 6 feet, with a depth of 3 feet, and an inclination of 20 feet per mile; its sides are rough, being cut in part throu

ref

2.8,

n

hough these were made as regular as practicable; the boiling action of the water passing around these curves brought the flow line (Q = 3

ref

× 2.83

2.8,

n

pe,[6] 1.41

ue to imparting velocity to

ng values of n, in v = n

, with shar

lume, with sh

ith asphalt, but with rivet-heads forming not

6

ctions American Society of

E HYDRAU

steam power; nevertheless it must be obvious that the current of the canal itself, slow though it may be, is quite sufficient to raise a small portion of the discharge to the very moderate height generally needed to lift it over the banks into the adjoining fields. Why then is it not employed for the purpose? The answer is obvious, when we consider the various hydraulic motors at present in use. Of course, motors worked by water pressure must here be excluded; and we are left with scarcely anything but the u

E HYDRAU

nected to the outside edge of the parachute. Thus they act like the spokes of an umbrella to prevent the parachute from opening too far under the pressure of the current. The parachutes must be placed so far apart that the current may act fairly on each, and the sum of the pressures forms the force which draws the rope through the water. The moment, however, that any parachute has passed round the return pulley, the current acts upon it in the opposite direction. It then shuts up like an umbrella, and assumes a volume so small that its resistance on the return journey is insignificant. After p

ng the rope. Secondly, the ease with which it is erected and set to work. Thirdly, the small part of the river section which it occupies, so as to present no obstacle to navigation. Fourthly, the ease with which it can be mounted on a barge of any k

length of the drums, and to these chains were fixed wooden blades or arms of a curved form, and so jointed to the frames that they opened when moving in one direction, and closed down on the chain when moving in the other. In this machine the weight of the chains was a serious obsta

is easily explained by the fact that the velocity of a current always diminishes as it approaches the bottom. Hence the pressure on the lower part of the parachute will be less than that on the upper part; but the former pressure tends to draw the parachute downward, while the latter tends to raise it to the top of the water. Thus, the latter being the larger, the parachute will always have a tendency to rise. In fact, it is necessary t

50 parachutes of 17.2 square feet area. As half of these are in action at the same time, the total working area for the two cables is 5,860 square feet. This immense area furnishes a considerable amount of power even in a river of feeble current. Comparing this with a floating water wheel of the type sometimes employed, and supposi

ept in a vertical plane, but lying at a slight angle to the direction of the current; and this acts to keep the two moving ropes apart from each other. The two return pulleys are, however, connected by a line, E, which can be shortened or lengthened from the pontoon, and in this way the angle of inclination bet

., which is by no means an impracticable quantity, we have T = 0.328 H.P. per sq. m. We may check this result by the equation given, in English measures, by Rankine-"Applied Mechanics," p. 398-for the pressure of a current upon a solid body immersed in it. This equation, F = 1.8 m A v2 / 2g, where m is the weight of a unit of volume of the fluid-say 62 lb.-A is the area exposed, and v the relative velocity of the current. Mr. Jagn finds that the maximum of efficiency is obtained when the rope moves at one-third the velocity of the stream. If this velocity be 3 feet per second, we shall have v = 2. and we then get F = 7 lb. per sq. ft. very nearly. Now 1 sq. meter = 10.76

After five months about one-fifth of the parachutes had to be replaced, but after seven months the hemp rope still showed no signs of wear. We think we have said enough to show that for certain purposes, and especially, as we have, already mentioned, for irrigation purposes, the new motor is well worthy of a careful a

SHAFTIN

sult of thirty years' experience in the manufacture of shafting, with many year

SHAFTIN

much shorter bed may be used, and the hollow driving spindle enables any length shaft to be turned, with one setting of the tools. The tool rest is so arranged as to allow of perfect lubrication of the tools, keeping the shaft cool, and at the same time holding it perfectly rigid

urned by a quick feed, and stops automatically, allowing nearly time enough for the oper

and they say that with a good quality of iron they have

AIGHTENIN

receives a rotary motion by friction, and shows the crooked places in the same way and with the same ease as though rotating on centers in the usual manner; vertically adjustable blocks are arranged in the base of the press to support the iron; power is applied by means of geari

AIGHTENIN

for different sizes of iron by tur

h of iron can be straightened, and the most laborious and disagreeable work in the process

MINING IN

RGE O'

survey remains of the rude but effective contrivances used by them in later, but still remote, periods, with full evidence as to the extent of their operations, in the numerous perpendicular shafts located at short distances from each other, over large areas of auriferous gravel in India, as well as from precisely similar memorials of ancient workings which remain also further demonstrations, in the abandoned "hill diggings," and shifted beds, and beds of rivers, in Peru Sou

rsed by the subsequent disintegrations and denudations of the mountains themselves, and deposited in a disengaged form for the first comer; and so perfect were sometimes these concentrations, in certain localities where water once streamed, that, divested of its earthy matrix, the cleansed pure metal was found deposited, detained by its superior specific gravity, on the bare rock, and only hidden from vision by a slight covering of vegetable mould. In this manner, as an example of such concentration, a "

t doubt several miles higher than they are at the present time-probably 20,000 feet above the sea-level-and of which, or whatever superior elevation they formerly had, the greater portion of it has already been removed, by the continuous natural action of centuries, to form there, as elsewhere, the plains and prairies of the earth, burying and diverting by the mutation the ancient river system, whose sources of supply were consequently extinguished by the removal of these altitudes. These denudations and subsequent depositions have been caused by alternations of temperature and combined action of air, water, and time since the creation of the world; and powerful demonstrations of these transformations instruct us in all direction

extinguished channels of ancient rivers, and whose now diverted waters were also the powerful agent to assist in causi

hout this necessary cementation its further removal is very certain when again attacked by water. An example of this continuous process is very observable in "Death Valley," Lower California, where a width of about 100 miles has been filled up from the hills to the gulf of same name, invading and occupying its former bed; and this activity is still proceeding, and a tempora

ore not immediately operated upon, and remained in abeyance, while the lower, richer, and more manifest alluvials endured. They were designated "blue gravel," the color being due to the action of sulphu

a well-defined channel on the bed rock, being the well-worn path of an ancient river; and it is obv

el and region near Smartsville, and 2,000 feet above the Yuba River, where snow is unknown, and near its terminus the ancient river bed courses more westerly than it does above it, and crosses Yuba below Timbuctoo, where the auriferous depositions disappear. The whole distance of 40 miles has been ransacked by the earlier adventurers, and around the village of Timbuctoo was a center famed for its wonderful yield of gold, obtained chiefly in the ravines, in holes, and depressions in the bed rock. These hollows detained the concentrations of the denudated alluvium from the altitudes, and were generally closely beneath the surface, and by such guidance and means of discovery the miners traced the gold up the ravines to their sources in the lofty mounds and deposits, or hills of cemented conglomerate, near Eureka

iption of Hyd

struction of a canal or canals, to convey the requisite volume of water from the fountain-head, and of sufficient elevation to command the ground to be worked upon, having also in view the le

, as the ground cannot be properly tested until the water arrives upon it, and disputes may arise between the shareholders of the

these beds can be easily traced by landmarks and undulations, and occasional exposures of the bed rock at low levels; also trial shafts are sunk in various places in search of it, to a depth of 100 feet, passing through blue gravel. The grades of the

d to the miner by huge pipes made of wrought iron, and laid down to follow the curvatures of the surface of the ground; and the pipe I now treat of, belonging to the Excelsior Water Company, has a diameter of 40 inches on a len

ents from fire and storms, and have the convenience for conveying the water from point to point, as the work of excavation advances, necessitating the removal of portions of the aqueduct fo

not exceed 20 inches in the plains beneath. The height of the reservoir above the tailing, or Yuba River, is 393 fee

fice, would give 50 inches, or about 89,259 cubic feet of water, flowing during ten hours per day, being an amount necessary for a first-class operation. The capability of the Excelsior Canal in rainy seasons reached to a delivery in twenty-four hours, to the various mining companies, of 21,120,000 cubic feet of water, or 8,000 miner's inches, and the value of the water paid for by the Blue Gravel Company in forty-three months ending November 9, 1867, was 157,261 dollars, being at the rate of 15 cents of a dollar per miner's inch;

nt

t 15 cents per m

wder, sluices, and s