And by such a code it would be perfectly easy for the conductor of the experiment to give every requisite direction for the application of the magnets, at any distance to which the blows could be distinctly heard.

At distances, however, beyond the limits of communicable vibrations, the application of the magnets must be by preconcerted arrangement. In this case a certain moment of time might be agreed upon for the application of the magnets; and given intervals arranged when the magnets should be reversed, and when neutralized.

Though, in the preceding investigations, the equal permeability of solid substances generally has been verified or assumed, nothing has yet been stated in respect to the effect of the interposition of metallic iron on the action of the magnet. This substance, the action of which on the magnetic needle is so peculiar, has indeed been made the subject of very particular and diligent investigation, but the results have been intentionally omitted, both because these results are somewhat different from all the others, and because iron, in a metallic state, is not likely to be met with in mining, so as in any way to affect the universality of application of the process herein suggested for the measurement of distances otherwise indeterminable.

Thus much, however, may be briefly mentioned, that iron, in any state in which it can be had, whether malleable or cast, whe

4, 1. Is the magnet against wall? 4, 2. Is the magnet neutralized?

4,3. Yes!

4, 4. No!

4, 1. It is against the wall.
4, 2. It is neutralized.

4,3. Yes. It is.

4, 4. No. It is not.

1, 2, 1. Lay aside the magnet till di- 1, 2, 1. May we lay aside the mag

2, 1, 3. Where is the magnet placed? Answer by signal of other column.

ADDITIONAL SIGNALS TO BE FILLED UP.

2, 2, 1; 2, 2, 2; 2, 2, 3; 2, 3, 1; 2, 3, 2; 2, 3, 3; 3, 1, 2; 3, 2, 2; 3, 2, 3; 3, 3, 1; 3, 3, 2; 3, 3, 3; &c.

N. B. The separation of the number of blows by a comma, denotes a sensible pause between each series.

ther in steel tempered or soft, does not prevent the influence of the magnet being transmitted to the compass; but, on the contrary, I have most commonly found, that the deviations produced by the magnet acting through a mass of iron, are greater than when nothing whatever is interposed. I have also found that the influence is not interrupted, though the interposed metal be a mass of hardened steel, nor even when trial was made on a body of powerfully magnetic bars, two or three inches in solid thickness. When the mass of iron is not otherwise magnetic than as to its magnetism of position derived from the earth, then the action of a magnet passed through its neutral or equatorial plane, is, in all cases, (as far at least as can be inferred from very many trials), more energetic than when no such substance is near it. This was so particularly the case when the magnetic influence was passed through the two double cylinders and furnace of a locomotive steam-engine (consisting of ten successive plates of iron, forming a total of 5 inches in thickness of metal), that it required the magnets to be a foot nearer to the compass in free space, than when placed beyond the engine, to produce equal deviations. For, whilst the distance of the magnets and compass, when the influence was transmitted through the engine, was 7 feet 8 inches, the distance on the open side, producing the same deviation, was 6 feet 73 inches*.

Now this anomaly may be easily shewn to arise from the development of magnetism in the mass of iron, through the proximity of the magnets, by which the direct or permeable influence of the magnet is necessarily augmented; but that the whole of the effect which takes place is not due to this cause,—what is generally called "induced magnetism,”—but chiefly to the actual transmission of influence through the very substance of the mass of iron, I have distinctly and experimentally determined.

Some working engineers, who were present when this experiment was made, were exceedingly inquisitive about the effects produced, watching the deviations of the compass with great astonishment. One of them perceiving that the magnet, which was hid from his view by the engine, equally affected the compass as when presented in the open space, addressed himself to his comrade, and made this characteristic remark," Why, Tom," said he, "it sees through't!"

On the 19th of April 1808 there was a heavy fall of snow for four hours.

1808.-A fine productive harvest, and but little blight.

Last week in April 1809, very cold, wet, frosty, and unpleasant weather.

May 1809 came in very fine and hot.

1813. An immensely productive harvest, and a general thanksgiving for it.

January 4th 1814, the deepest snow that has been known for 40 years began, and it continued on the ground for five weeks: at some places the drifts were 15 feet high. The frost continued 12 weeks to March 20. 1814.

1816.-From April 12th to 15th snow remained on the ground, and the weather was exceedingly cold and frosty.

1816.—September 3d, a hard frost which produced ice. 1817.-The month of August very wet, succeeded in September by fine harvest weather till November.

1818.-May 8th, a deluge of rain fell, after which no more rain fell at Treveroux or near, till September 5th, 17 weeks and one day, and all vegetation was completely burnt up.

1819.-October 22d, Snow six inches deep.

1822.-No rain from May 2d to July 5th, nine weeks of very hot days.

1823.-Rain little or much every day from June 29th to August 15th.-47 days.

1824.-A very wet summer, but not cold; crops of corn slight of hay heavy.

1825.-Sold the produce of 12 acres of hops for 5s. 1826 and 1827.-Two fine summers.

1828.-Very heavy rain every day from July 6th to August

14th.

1829.-Though the 9th of April is stated as the day on which oat-sowing was finished, yet an experiment was tried, by sowing white gate field with black Tartar oats, on the third of May. The weather was much against them at first, but they turned out very well, and were carried in on the 7th of October.

Rained more or less every day from the 16th of June to 20th September, except on four days, the 23d and 24th of July, and the 3d and 4th of September.