parallel bars or thread-like lines. In some of their aspects these clouds resemble a kind of cobweb, stretching their white and delicate fibres between the dark and denser masses. Being situated above the line of congelation, they are supposed to be composed of very fine particles of ice. They occupy the most elevated positions of cloudland, and are supposed to indicate variable weather.

are:

The Cumulus, or stacken-cloud, is an accumulation of clouds stacked or piled into one large and elevated fabric, and is generally the forerunner of fine weather. This cloud occurs in the lower regions of the atmosphere, and is ordinarily under the control of surface winds. The Stratus, or fall-cloud, is composed of all those fogs and creeping mists which, in the calm evenings of summer and autumn, spread like a mantle over the valleys, plains, lakes, and rivers, and is said to indicate the continuousness of fine weather. It is a night cloud, taking its departure when the day appears. I have seen this cloud extending over the surface of a river or sheet of water, without passing the boundary of its banks. Sir Humphrey Davy explains the phenomenon by the difference in the rate of cooling of land and water. His words "As soon as the sun has disappeared from any part of the globe, the surface begins to lose heat by radiation, and in greater proportions as the sky is clearer; but the land and water are cooled by this operation in a very different manner; the impression of cooling on the land is limited to the surface, and very slowly transmitted to the interior; whereas in water above 40° Fahr., as soon as the upper stratum is cooled, whether by radiation or by evaporation, it sinks in the mass of fluid, and its place is supplied by water from below, and till the temperature of the whole mass is reduced to nearly 40° Fahr., the surface cannot be the coolest part. It follows, therefore, that wherever water exists in considerable mass and has a temperature nearly equal to that of the land, or only a few degrees below it, and above 40° Fahr. at sunset, its surface during the night, in calm and clear weather, will be warmer than that of the contiguous land; and the air above the land will necessarily be colder than that above the water; and when they both contain their due proportion of aqueous vapour, and the situation of the ground is such as to permit the cold air of the land to mix with the warmer air above the water, mist or fog will be the result."

The Cirro-cumulus, or sonder-cloud, is a rounded mass of distinct clouds arranged in extensive beds. Bloomfield's description is graphic and truthful:

"The beauteous semblance of a flock at rest."

The Cirro-stratus, or wane-cloud, is a flat cloud of great horizontal extension, narrow in proportion to its length, and very thin at the

edges. Sailors regard this cloud as an indication of coming wind, rain, or tempest.

The Cumulo-stratus, or twain-cloud, is a cloud formed by the junction of two clouds, or of masses of rounded and fleecy clouds, and is the most imposing and magnificent form of cloud. The formation of such clouds takes place under different temperatures, and may be the herald of snow and thunder storms.

The Nimbus, or rain-cloud, is the least interesting arrangement of the clouds to the eye. This cloud may be formed either by two clouds, or two air-currents of different temperatures coming together, when the general blackness gives way to a lighter shade. This change may often be seen at a distance, and the shower observed to be moving in the direction of the wind.

There are a number of very mysterious processes going on in the atmosphere, which are untraceable by the eye of man, but which result in the rearing aloft of clouds in all conceivable forms and positions. The common air is chiefly composed of two gases-namely, oxygen and nitrogen. Besides these, however, is a quantity of invisible vapour insinuated between the particles of the gases; and this vapour is the result of the ever-active agency of heat and electricity, which, by a very wondrous subtlety and energy, raises the waters from the surface of the earth, and transfers them for a season to a new and romantic dwelling-place. This change or metamorphosis of the waters into vapour is constantly going on, and not only is moisture constantly being gathered from the oceans, lakes, and rivers, but also from the gardens, pastures, and forests. Mr. Leslie states that ploughed land supplies as much water to the atmosphere as an equal sheet of water. The capacity of the atmosphere to receive invisible vapour depends upon temperature, and is invariable in its extent at the same temperature. When the interstices of the gaseous fluid are full, the air is said to be at its point of saturation, and all further increase becomes visible in the form of mist, steam, or cloud. The lower the temperature the greater is the condensation of the air, and the consequent tightness or closeness of its particles, and the less the amount of moisture that can enter it; but with an increase of the temperature there is an expansion of the capacity to receive moisture. The formation of these vapours into masses generally takes place in the high regions of the air. Mr. Leslie says that we may "estimate the position of extreme humidity at the height of two miles at the Poles, and four miles and a half under the Equator."

Dr. Dalton remarks that the small fleecy patches of cloud which we observe are frequently from three to five miles in height. There can be no doubt that the height varies with the seasons of the year, and

that the clouds are oftener under than above a mile in altitude. They generally form under the action of air currents, in consequence of a decrease of temperature, and a due supply of watery elastic vapour being present in the parts where the clouds arise. Sometimes we look upon the sky, and everywhere it seems clear, without a cloud in sight; we look again in a few seconds, and we find clouds, while we have failed to detect any movement amongst them whatever. No doubt in such a case the clouds have been formed by the action of cold air currents. This accounts for the clear blue sky in one part, and cloud-patches in another, the clear blue alternating with visible vaporous structures.

The clouds have long been supposed to consist of very small globules or bubbles of water filled with air, because the water globules must be superficially heavier than the air. Dr. Saussure first taught this idea, which has generally been adopted. The fact, however, was overlooked that if particles were only small enough, they might be kept suspended in a liquid or even in a gas, notwithstanding the material of which they consist being heavier than the medium in which they float. Dr. A. Smith has found the particles to be solid throughout, and treats the theory of the particles consisting of hollow spheres or vesicles as an absurdity. Those who prepare polishing-powders know that heavy materials, when very finely pulverised, may be kept suspended in water for days and weeks together. The finest emery-powder is only obtained from water, from which the heavier or coarser particles have been deposited, in times varying according to their fineness. It sometimes takes weeks for the very finest to settle. On a microscopic examination of the air of a room that has been closed for weeks, we shall find particles of heavy materials still floating, and if in the neighbourhood of machine shops we shall recognise metallic dust.

The power which holds up these materials is adhesion, which increases with the increase of the surface of the floating body. The finer the dust the larger is the amount of surface as compared with the volume; and when this adhesive action of the liquid or gas becomes great enough it overcomes gravitation, and the particles are kept floating. The water-dust thus floating as clouds must be marvellously small. Dr. A. Smith, when in Iceland, observed a cloud or fog rolling down the streets like dust or smoke; the particles were about 1-400th of an inch in diameter, and were the largest he had ever seen. That a strong adhesion exists between air and water may be seen by the effect produced by wind on water. The wind forces or ruffles

up the water; but cover the water with a film of oil, and the wind will scarcely cause a ripple. There is not the friction or adhesion of the wind upon oil that there is upon water.

The clouds, then, are composed of water-dust, sometimes in a liquid and at other times in a congealed condition, and float in virtue of the large amount of surface presented to the air. This water-dust becomes visible after the saturation point has been reached, which point varies with the temperature of the air.

Hoping I have succeeded in making this subject intelligible to you all, I remain, truly yours,

J. BOYES.

PAPER FROM NINGPO.

BY MRS. SWALLOW.

"There is a Love that does not cease,
Though sin the hardened heart enthrals;
There is a Voice where'er we be,

That gently says, 'Come unto Me.'"

"N the eastern suburbs of the populous city of Ningpo, almost at the

the upper room of what was once a native shop and is now our street chapel, I meet on Sabbath afternoons a class of mothers and daughters. The place is about two miles from my own house. I reach it by means of a sedan-chair, which carries me through crowded streets, the many anxious faces the expression of which I catch, and which lingers with me as I am hurried along, stirring up my desire to give the Gospel in its soothing power to those I am so shortly to meet. By and by we come to the bridge which divides the city from its suburbs. Here, teeming with life, are eager buyers from the country, and still more eager sellers; passing hastily along are some holding in their hands portions of the Scriptures. We find the key to this in the familiar form of Mr. Williams, of the Ningpo Customs, who is standing closely surrounded by Chinamen trying to get a peep at the books he is offering for sale. A few minutes more, and we have reached our destination. Why did I go so far away? About two years ago a middle-aged woman carelessly entered the chapel, and the foreigner who was present, noticing the unusual interest she showed, invited her to come again. She received the word gladly, and in company with a widow-lady was a few months afterwards baptized. They occasionally visited me, really desiring instruction, so I decided to teach these women, and one or two others they had gathered round them. Would not a correct and increasing knowledge of our holy religion shed a halo of light around them, which some time in the future should by its glow attract and win the weary ones on whom its rays fell?

Yes, here was an open door; the very one I had sought for so long, which, while it won my symathies, appealed to my judgment. We commenced our class. We spoke together of present duties and of their heathen neighbours. At once came the query, "Well, what of these ?" “Why, call them in; repeat to them the old story of Jesus and His love." They responded to the invitation, prompted partly by curiosity, partly by that longing of the human soul for truth, that groping in the darkness if haply it may find the light, so that the character of my class early assumed an altered form. There is now a varying attendance of about twenty.

A real difficulty was to be met-viz., how to present the Gospel so that while it taught the heathen it should yet stimulate and instruct those who had become familiarised with first principles. Here it will be necessary to state that I did not, and do not, employ a native Bible woman. Remembering a Christian woman, who had been well and carefully trained, but who from family and other reasons had almost ceased attendance at public worship, I visited her, putting to her the question, "Will you join us at our meeting ?" To my surprise she gave a cheerful and willing assent, and has in various ways rendered most valuable assistance. Living opposite is a young girl who has received some instruction in our school; it is pleasing to notice the many little ways in which she aids us.

A word or two as to the kind of teaching most appreciated here. Simple forms of prayer and small tracts in the Chinese character are readily learnt, and as preparatory work do good service. Three women have made a little progress in the Romanised system; one being able to read the hymn-book slowly.

Still it is only fair to state that those who are sincerely desirous of acquiring this latter method of reading are the exception. As an encouragement to those who distribute, broad-cast, papers containing religious truths, one woman told how she had been visiting at a distant place, and seen one of the many forms of prayer plastered on a wall. Aided by those living near she had memorised the whole of it, and repeated it to us.

A rapid glance at the most interesting women will suffice for our purpose. One, a vegetarian, possessing a shrewd, keen face, and practical business manner, is one of our most eager and attentive listeners. Another, who comes in with a bundle in her hand, is on her way to the market boat. She stays but a short time; still her earnest, receptive mind is a promising soil.

One who first heard the message of salvation about two years ago has now joined us, and has been baptized. There are also two candidates for baptism. Then there are a few whose aged forms and

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