"I fear thee, ancient Mariner!".

"Be calm, thou Wedding-Guest! 'Twas not those souls that fled in pain Which to their corses came again, But a troop of spirits blest.

Swiftly, swiftly flew the ship,
Yet she sailed softly too:
Sweetly, sweetly blew the breeze-
On me alone it blew.

Oh! dream of joy! is this indeed
The lighthouse top I see?

Is this the hill? is this the kirk?
Is this mine own countree ?....

Since then at an uncertain hour,
My agony returns :

And till my ghastly tale is told,
This heart within me burns.

I pass, like night, from land to land;
I have strange power of speech;
That moment that his face I see,
I know the man that must hear me :
To him my tale I teach.

What loud uproar bursts from that door!

The wedding-guests are there;

But in the garden-bower the bride

And bride-maids singing are:

And hark the little vesper bell,

Which biddeth me to prayer!....

O sweeter than the marriage feast,
'Tis sweeter far to me,
To walk together to the kirk
With a goodly company!

To walk together to the kirk,

And all together pray,

While each to his great Father bends,

Old men, and babes, and loving friends, And youths and maidens gay!

HOW COAL AND THE STRATA IN WHICH IT IS FOUND ARE FORMED.-PROF. A. H. GREEN, M.A., F.R.S.

1. THE Coal Measures are made up of different kinds of rocks. In the main, we may say that there are five different kinds of rocks in them. There are sandstones; you all know what a sandstone is. There is the rock named shale by geologists, which is known more popularly, especially amongst miners and colliers, by the name of "bind;" there is limestone; there is coal itself; and there is a peculiar sort of clay always found under each bed of coal, which is sometimes called the under-clay, and goes by different names in different parts of the country. In Yorkshire we generally call it "spavin ;" and I think in Lancashire you know it by the name of "warrant," or "seat earth." Of these rocks the sandstones and shales show that they have been deposited under water; that is to say, they are divided into a number of layers lying one on the top of another, somewhat in the same way that a pile of volumes lie when placed on the floor of a room. In fact, these sandstones and shales are nothing

more than sand and mud that has been washed off the face of the ground by rain, carried by rain into brooks, by brooks borne on into rivers, and swept along by the rivers till they entered the comparatively still water of the sea or a large lake, and then let fall to the bottom.

2. We will begin with the shales, which are nothing in the world but hard clay, splitting up, in most cases, readily, into a number of thin parallel layers. We must first of all note that the matter out of which rocks deposited under water had been formed, has been carried down in two different ways. When this matter is light or finely divided, it can be held in suspension in the water of the river which bears it along; if it is coarse or heavy, it can only be carried forward by being pushed along the bottom. The first sort of sediment makes the river muddy; the second sort, which is pushed along the bottom, causes a peculiar grating and rolling sound, which you may often notice by patiently listening as you float quietly in a boat down any large river. Shale, which we are now considering, has been formed of very finely divided mud, or of a mixture of such mud with very fine sand; and, consequently, the materials out of which it has been formed were, as a rule, carried in suspension. When the stream which carried them along entered the sea or a large lake, its velocity was checked; but this finely divided matter did not necessarily fall down plump at once to the bottom, but was carried forward very often to long distances by even the small amount of velocity which the stream was enabled to retain. And if the sea into which it was borne was traversed by currents or was subject to tides, these currents and tides would still further aid in spreading out this finely divided sediment over larger areas. Again, if there were any interruptions in the supply of sediment, any pauses in this supply, each layer, when it had fallen down, would have time to harden slightly before the next layer was placed above it; and in this way the bedded structure of shale, in virtue of which it splits up into fine lamina, has been produced. You see, then, that, on account of the very gentle regularity with which the finely divided matter out of which shale has been formed settled down, shales will show great regularity of thickness over a large area, and will extend to very great distances, far away from the mouth of the river which brings down this matter; and, upon the whole, the general character of shales will be uniformity of composition and regularity of bedding over very, very large That is the notable feature about the shales.

areas.

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3. We next come to the sandstones, which are formed of a mass of sand, or quartz;" and because sand or quartz is a very hard substance, it is not easily ground down to a finely divided state, and, therefore, its grains are large; also quartz is a heavy substance. For these two reasons, the materials out of which sandstone are formed cannot be carried in suspension: but, as a rule, except the current be very violent, the only way in which it can be borne down in ordinary currents is by being pushed along the bottom. When a running stream that is pushing forward this sandy matter enters still, deep water, its velocity is checked, and the sand, instead of being carried out to very great distances far and wide, like the finely divided silt out of which the shale was formed, sinks rapidly to the bottom and accumulates in a bank of a wedge shape, which forms near the mouth of the river that has brought down the matter. So that we get constantly in that way formations of sandstone near the shore, and of shale far off the shore, going on simultaneously.

4. We next come to limestone. Limestone was not formed out of sediment carried down by rivers into seas or lakes. It is mainly made up of carbonate of lime, and sea water contains a small quantity of carbonate of lime in solution. Now, there are certain animals that live in sea water, shell-fish, corals, &c., which have the power of extracting this carbonate of lime from the sea water, and out of it building up the hard dwellings in which they live, or some part of their animal organism. On the death of these animals, their hard parts, which are formed of pure carbonate of lime, fall to the bottom of the sea, and there accumulate in a great heap, and this great heap, by pressure and chemical changes and other agencies, is afterwards turned into limestone. These animals that secrete the carbonate of lime from the sea water, as a rule, flourish only where the water is clear; they cannot live in muddy water; and therefore they are found, as a rule, in water so far distant from the shore that no sediment borne by rivers can reach them. From this fact we draw a very important conclusion-that wherever we find a great mass of nearly pure limestone, we are quite sure that at the time the limestone was formed the spot where it is now found was far out at sea; but wherever we find the limestone becoming earthy, and intermingled with sedimentary deposits, such as sandstone and shales, we know then that we are getting near the old coast line.