Five successive waves of considerable height are spoken of as having occurred at Simoda, while by the gauge we trace eight, of which seven are of considerable height. The highest wave at Simoda was estimated at thirty feet, at Peel's Island fifteen feet;-at San Francisco it was 0.65 feet and at San Diego in the first series 0-50 feet.

At San Diego the same three series of waves are distinctly shown. The first begins 1h 22m later than at San Francisco, correction having been made for the difference of longitude, and ends 0h 52m later. The interval is 30m less than at San Francisco, the oscillations being rather shorter than at the last named point. The second begins at 0h 54m later than at San Francisco, and ends 34m later. The third begins about 54m later than at San Francisco. The average time of oscillation of the first set of waves is 31m, and of the second 29m, being respectively 4m and 2m less than of the corresponding series at San Francisco.

The average height of the first set of waves was 17 feet lower than at San Francisco, and the second as much higher. This fact taken with the difference in the times of oscillation leads me to suppose the difference in the two series due to interference, which is also suggested by the position of San Diego in reference to the islands separating the Santa Barbara sound from the ocean.

The general analogy in the succession of heights of the mean. of the two series as shown in diagram No. 3, C, and in the times as shown in D of the same diagram, is very satisfactory.

The difference in the periods of the tide at which the waves occurred would tend to cause discrepancies.

The first series occurred on a rising tide of 4 feet, while at San Francisco it was upon a falling one of 2 feet. The second began near high water and was chiefly upon a falling tide of 7 feet, while at San Francisco it was upon a rising tide of 4 feet.

The forms of some of the individual waves in the second series at San Francisco and San Diego, accord remarkably, as those marked 1, 3, 4, 5, and 6, when reduced to the horizontal line. The comparison on the curve where the distortion remains is also very instructive. The waves marked 1, 4, 6, and 7, are not unlike in the first and second sets at San Diego.

The observations at San Diego confirm then, in general, the inferences derived from those at San Francisco.

The register at Astoria throws no new light on the subject. The bar at the entrance of the Columbia river would explain why the oscillations were lost or greatly reduced at Astoria, even if they arrived off the entrance of the river. The disturbance is marked on the register but in an irregular and confused manner. It was also apparently preceded by unusual oscillations of the

water.

SECOND SERIES, Vol. XXI, No. 61.-Jan., 1856.

After allowing for the very free action of the float of the San Diego gauge, there appears to have been indications of disturbance previous to the great earthquake shocks and following them, occurring at intervals for several days after the 23d of December. The San Francisco gauge presents similar indications.

No special effect appears to have been produced upon the time or height of high or low water by the earthquake which merely caused series of oscillations upon the great tidal wave.

I now proceed to draw from these results some conclusions as to the progress of the ocean wave accompanying the earthquake. The latitudes and longitude of the places referred to, are as follows:

The distance from San Diego to Simoda from these data is 4917 nautical miles, and from San Francisco to Simoda 4527 nautical miles.

According to one account the disturbance began at Simoda at 9 A. M. or 22d 23h 44m Greenwich mean time, and the first great wave half an hour after. The first disturbance at San Francisco was at 23d 4h 12m, or 12h 28m after that at Simoda, and the first great wave at 23d 4h 42m giving the same interval. The distance and time from this account give for the rate of motion of the wave 363 miles per hour or, 6.0 miles per minute.

The second account would give for the time of transmission 12h 13m, and for the rate of motion 370 miles per hour, or 6.2 miles per minute.

The San Diego observations give for the time of transmission of the wave from Simoda to San Diego 13h 50m by the first account, which combined with the distance gives 355 miles per hour, or sensibly the same result as derived from the beginning at San Francisco. The first great wave would give identically the same result.

From the results obtained we may determine the mean depth of the Pacific ocean in the path of the earthquake waves. We have found for the rate of motion, from 60 to 6.2 miles per minute, and for the duration of an oscillation 35 minutes at San Francisco and 31 at San Diego. This would give for the length of the wave on the San Francisco path 210 miles to 217 miles, and on the San Diego path 186 to 192 miles.

A wave of 210 miles in length would move with a velocity of 6.0 miles per minute in a depth of 2230 fathoms. (Airy, Tides and Waves, Encyc. Metrop., p. 291, Table II.) One of 217 miles with a velocity of 6.2 miles per minute in a depth of 2500

fathoms. The corresponding depth on the San Diego path is 2100 fathoms.

The disturbance of the 25th of December presents at San Francisco three sets of waves of seven each, and at San Diego one set of seven, agreeing in their general features with those at San Francisco, and then a set of seventeen, in which at first, intermediate waves seem to be wanting at San Francisco, or which have no analogous oscillations there. The crests of the first set occurred at a mean about 17m earlier at San Diego than at San Francisco, the heights on the average were nearly the same, being 39 feet at San Diego and 44 feet at San Francisco, and the time of oscillation at the two places the same, namely 41. The origin of the disturbance was probably nearer to San Diego than to San Francisco.

ART. VIII.-Description of a Self-sustaining Voltaic Battery; by GEORGE MATHIOT.*

MANY inquiries have been made in regard to the principles of construction of my battery, with commendation of its working properties, and I have even received large commercial orders for its construction, which, of course, I could not execute, so that, up to this time, a few sets only have been made for use in government works. I now give a thorough description of the battery, and of the principles on which its action depends, hoping that thereby the recent important applications of voltaic currents may be facilitated through my labors.

The first forms of the voltaic battery were so expensive and cumbrous, and withal so uncertain and fleeting in action, that the idea of applying galvanic currents to the great business affairs of life would certainly have gained nothing more than a smile from even the most sanguine philosopher. But, from the continued researches of electro-chemists, the world has now the benefit of electro-metallurgy and the electric telegraph. Even the batteries now employed are uncertain to a considerable degree, and require constant attention. Any consideration, therefore, tending to the improvement of the instrument, so as to avoid the necessity for frequent attention, cannot but be appreciated at this time, when the world is asking science for a telegraph across the Atlantic, and we are looking for a line from the Pacific to the Mississippi, on which there must needs be many stations or relays of batteries, that from the uninhabited state of the country cannot be constantly attended or even frequently visited.

* From the Report of the Superintendent of the Coast Survey, 1854. Washington: 1855, p. *193.

The construction which I have devised will, I think, obviate many of the difficulties attending telegraphing; and the principles of electro-chemistry, and even experience, justify me in saying that batteries may be constructed to be buried in the earth or sunken in the sea, which will certainly and uniformly continue in action for very long periods, even for a hundred years.

In my battery there is no new element, neither is the form such as to attract attention in respect to anything in it materially different from the batteries now in use. It is only in all the parts being constructed with rigid adherence to the principles of electro-chemistry that its peculiarity consists, and therefore a consideration of the principles is necessary to its appre

ciation.

A charged voltaic battery may be considered as a factory of electrical power, just as a charged and ignited furnace is a factory of heat, and similarly in both cases the rapidity with which the fuel is consumed, and the steadiness of action, will depend on the arrangement of the parts. A furnace in action consumes the fuel; whether the generated caloric be applied to use or suffered to run waste, the chemical affinity will sooner or later consume the fuel; and though the action may be diminished to some extent by cutting off some of the conditions of combustion, the extent of that action will depend on the construction of the furnace. If a furnace could be made so that we might draw off the requisite amount of caloric to boil a pound of water just as it might be required, and retain the residue until we again had occasion to use the fire, then such a furnace would be a storehouse of caloric, just as a granary is a storehouse of grain from which we draw a supply, and keep the residue in store.

The same remark will apply to the battery; once charged, the chemical affinity consumes the material sooner or later, usefully or not, and we can entirely arrest action only by unloading. Much indeed can be done by modifying the conditions of action, but, as in the furnace, all will depend on the construction.

To make a battery which can keep the action in reserve, is the problem of a depot of electricity.

The uncontrollable nature of the voltaic conditions, I conceive, to be the cause why batteries have not hitherto been constructed with reference to the whole amount of force, as well as to the strength or rate of working.

Previous to my own efforts I know of no attempts at putting a quantity of galvanic material in store ready for action just when required.

A cell of the reservoir battery is in form a four-sided prism of stone-ware, eight inches long, three inches wide and ten inches deep.

On the side, at the depth of three inches, is formed a trough or tray, an inch wide and half an inch deep, running the length of the side. This tray is made with the jars.

It is indispensable that the jars should be completely watertight, but they are difficult to obtain; and thus far I have had none which have given full satisfaction. The best were of chemical stone-ware, but only half of them were water-proof. A coat of glazing cannot be depended upon for sealing, as in vessels for culinary and table purposes, as sulphate of zinc penetrates even the beautiful stone-ware called "granite."

When unable to obtain good rectangular jars, I have used cylindrical glass jars, and formed the tray with cement on a plate of glass or gutta-percha, a little less in width than the inner diameter of the vessel. The plate can be kept from moving by projecting jogs, which catch on the edge of the vessel. The plate, tray, and jogs can easily be moulded in one piece in glass.

The conducting plate of the battery is of the platinized silver introduced by Mr. Smee; but the mode of preparing it is different. I first puncture it closely with a square-pointed awl. The holes should not be cut with a punch, which removes the metal, but formed by pushing the metal up in burs, like those on the common tin grater. In this way none of the surface is lost, and both sides of the silver are rendered efficient to a single surface of zinc. After the plate has been punctured, it should be well cleaned, and then electro-plated until the deposit begins to roughen; this very much improves the stability of the plate, and greatly augments the extent of surface. The cyanids should then be well washed away with hot water, and the plate be platinized. I find that the platinizing is very durable, if the arrangements for depositing the platinum are made so that the bright metallic platinum shall first be deposited, and the amorphous form (black deposits) gradually succeed it. The reguline deposit of platinum can readily be obtained by using a mixture of chlorid of platinum and chlorid of sodium, (instead of the acid solution of chlorid of platinum recommended for obtaining the black powder,) with a train of small batteries and a platinum electrode. The conducting plate is attached to a square bar of lead nine inches long, and five-eighths of an inch across the sides. The bar rests on the top of the jar, and is kept from moving horizontally by studs near the ends. At the distance of an inch and a half from each end of the bar is a pendant an inch long, and of nearly the same section as the bar. The plate is attached to the bar by sawing a slit a third of an inch deep in each pendant, in the direction of the length of the bar, inserting the silver in the slit, and thoroughly closing down the lead on the plate. This is conveniently done by biting the pendant in the jaws of a common bench-vice. In the side of the bar, near the middle, is