The longitude is quite a different thing. The aspect of sun, moon, or stars, will not directly give it, it is an artificial though necessary measurement, and is best discovered by artificial means; nature (as I have said) gives no phenomenon to distinguish the meridian of Greenwich from that of Paris or Vienna; we can tell how far the ship is North or South of the equator, but not so readily how far she is East or West of Greenwich. How can the required knowledge be obtained? The ship's noon can be found by observations made in the ship, how can we tell at that instant the time at Greenwich? for this is in fact finding the longitude. The young geographer, who knows what longitude on the earth means, hears perhaps that Harrison gained the prize offered for finding the longitude, by his constructing a very superior chronometer, and he does not perceive at once the connection (not to say identity) between them. Let him reason thus: the sun's meridian height at any place fixes the time of noon at that place, suppose then when it is found to be noon at sea any where, we could find out that at Greenwich the clock said two hours after noon, then the ship must be as far West of Greenwich, as the earth's revolution would carry any meridian through, in two hours, that is to say 30°; for if the sun is on my meridian at any instant, in one hour he will be over a place 15o West of me, in two hours over a spot 30° Westward of me, and so on. Consequently, if a ship takes out a good chronometer set to Greenwich time, the difference between the ship time by observation and the chronometer's time, will give the longitude at the ship.

There are other methods, which I will merely glance at. The eclipses of Jupiter's satellites are computed in the almanack for Greenwich time; suppose a satellite is set down as to be eclipsed at ten o'clock in the evening, and in the ship it is noticed to suffer eclipse at eight

o'clock, then eight o'clock in the ship, occurs at the same instant with ten o'clock at Greenwich, and the ship is two hours or 30° West of Greenwich, as before.

Again, the moon moves rapidly among the fixed stars; her distance from certain bright stars at a certain hour, (Greenwich time,) is set down in the almanack; these distances are observed in the ship, and from these the difference of time or longitude is discovered, by means of not very easy calculations. But a good chronometer, or by far the quickest way of finding this, the accuracy of lunar distances, depends on several conditions, and among them (of course) the nice knowledge of the lunar theory, and the correctness of the lunar tables.

The reader will understand, that I have only given the outline or principles of the methods employed; it would not befit the character of this magazine to do more, it would throw it out of use for general readers; but the heavens are worthy of our attention as much as the earth, and a paper on Astronomy is as admissable as one on Botany or Geology, into a publication which aims to glorify our God and Saviour, not only in the doctrines of his love in redemption, but in the marvellous works of his hands. If the Psalmist called upon men, to walk round about Zion, and tell the towers thereof, and mark well her bulwarks, may we not point to glories more enduring, the marks of creation's immensity, and the littleness of man? And I would have every astronomer pause now and then in his reasonings, and forbear his calculations, that he may think of the Creator of those vast orbs he watches, and recal the text which God spake concerning Jesus, "by whom also he made the worlds," true as this is for all he gazes on, though the text be strictly interpreted any other way; then shall head and heart be alike profited,

and the finest exercise of the intellect shall go along with the edification of the soul.

But to conclude this paper. We have spoken of 'noon,' and one kind of noon is observed, and another computed from it. The sun moves in the ecliptic with variable velocity; quickest in winter, and slowest in summer, and the ecliptic itself is not parallel to the equator, for both these reasons; solar days are of unequal length, and thence are unserviceable for measuring time. The sun dial marks solar days, but no watch or. clock could keep time with the dial, unless by miracle. If the watch gained or lost regularly, or went well, in neither case would it agree with the dial. But we must have days of equal length, if they are to be true measurers of time; if the sun in his orbit moved with uniform rapidity, and moved moreover in the equinoctial, then it is evident that (the earth's diurnal revolution being uniform) all solar days would be of the same length, and hence it is that astronomers have feigned a sun to move under these conditions, and thus securing equal intervals, they have applied to the true sun a correction commonly called the equation of time.' On the first of January, 1843, my almanack says, 'clock before the sun 3' 43",' this signifies that the imaginary sun crosses my meridian 3' 43" before the real; in other words, when the real sun is on the meridian, it is 3' 43" past clock noon: for clock noon is mean noon, or the noon marked by the fancied sun, which moves in the equator with the real sun's mean motion. Hence the time by a sun dial must always be corrected by the equation of time.'

ON PRIVATE BAPTISM.

THE order of the Church directs that baptism shall take place in the time of divine service, after the second lesson; but in cases of illness any child is to be baptized at home, the parents sending for the minister to do so. By a strange use of words, such child is often said to be half baptized;' what the meaning of such an expression really is, it would be hard to say. The following remark may be useful. Baptism is duly and sufficiently administered, when the minister uses water, in the name of the Father, and the Son, and the Holy Ghost; nothing can afterwards add to the reality of such baptism. When the child thus baptized privately is afterwards brought to the Church, the only additional service consists in the public profession of the sponsors, and the public reception of the child into the community of Christ's people; thus the water and the words of baptism are not repeated. If a child has been baptized by one who has no lawful authority to baptize, such as a dissenting minister, or other lay person, the Church holds that such baptism, though unwarranted and irregular, is valid; that is to say, it is not to be repeated by the lawful minister. It ought not to have been done, but it is valid when done. This question was much disputed in the early Church, but was generally settled as I have stated it. The Bishop, who alone has authority to commission men to baptize, has equal authority to ratify all irregular baptisms; so that in the rite of confirmation, the child who had no control over its own baptism in infancy, has the privilege of correcting the error and supplying the defect, of what might have been an irregular baptism.

Christ, before he ascended, gave to his eleven apostles, (none else were present,) the power of conferring baptism. Now it must either be that any person may

baptize any other, or else none have authority so to act, unless they have received it from those who have received it by a line of succession from these apostles. It does not require either learning or special shrewdness to see this. The clergyman can see his right palpably enough; all other christians stand exactly on a footing with each other. The apostles did not with their own hands baptize the converts, but it was always done under their bidding and authority.

If a parent concludes from scripture, that any christian is authorized to administer baptism, his error, if consistent, might lead him to act so to all his children : no such idea (that I am aware of) prevails. It seems hard to conceive, how a special authority could be given to a certain set of men, if Christ did not give it his apostles only, when he met them on the mountain alone. (Matt. xxviii. 16-20.) This power they could and did transmit, and every parent should look to it, whether his offspring receive this sacred rite by the hands of those authorized to confer it; he should say to him that officiates, "Who gave thee this authority?" If he cares not for the reply, he might as well baptize his children with his own hands. It is no want of charity, but an appeal to every man's common sense, when we say that a dissenting minister has no authority to baptize; nor can he pretend to it, without allowing the same right to all his congregation, for he never received any authority, beyond the conviction of his own mind; when and where, and how did he get it? who authorized him?

The clergy are bound to urge and practise the custom of baptism in full service, after the second lesson. Reasonable and godly people are not likely to object to this; but the parish minister cannot refuse to administer this holy rite, on other occasions. I do not speak of what he could do by law, but what he is bound to do in conscience. If the child be not sick, I am not