It will thus be seen that a complete percussion musket weighs ten pounds, lacking eighteen hundredths. This weight is less than that of the old flint muskets.

The exact cost of a single musket, of the number manufactured last year, cannot be stated, the inventory being uncompleted, but the cost in the year 1850 was $9 033. The cost for the last year will be less. In ten years, the cost of manufacture per musket has been reduced nearly one half, it being in 1841, $17 44.

The exquisite order and neatness which reign throughout the whole establishment, are always subjects of remark to those who visit it; and the perfect system of accounts by which every item of stock is followed and checked in its passage from the hands of the storekeeper to its final and perfect transformation into the finished arms, is enough to beatify one whose organ of order is dominant in his cerebral development. This intimate system of accounts is as prevalent in every other department as in that of stock, and is necessary in the making up of the quarterly returns to the department.

ORIGINAL AND SELECTED MISCELLANY.

(For the Register.)

THE PROGRESS OF ASTRONOMY.

PART I.-ANCIENT AND MIDDLE-AGE ASTRONOMY.

SECTION I

Origin of Astronomy-First cultivated by the Chaldeans, and afterwards by the Egyptians-Length of the Year-Egyptian Calendar-Sothic period-Greek Calendar-Metonic Cycle-Improved by Calippus-Roman Calendar-Various changes made in it-Reformed by order of Julius Cæsar-Subsequent changes-It supersedes all other modes of reckoning throughout Europe.

THE heavenly bodies so readily attract the attention of mankind, that they were noticed, with some degree of care, from the earliest times. Besides the interest excited by their appearance, it was necessary to observe their motions, in order to ascertain the proper times for performing the labors of the field, and making suitable provision for flocks and herds. When the Pleiades appeared in the west after sunset, it was time to plough; and when they rose in the east early in the evening, it was autumn. Another thing which drew attention to the heavenly bodies, was the opinion which prevailed at a very early period, that they controlled, not only the destinies of men, but even the growth of plants. The apparent influence of the sun, and the great regularity in the motions of the fixed stars, induced men to think them divine; and hence they were observed with care.

The Chaldeans, led by their clear skies and pastoral habits, appear to have been the first people who made any great progress in classifying celestial phenomena. After these followed the Egyptians, from whom the Phenicians probably borrowed the little they knew of the subject. The Sun and Moon were first observed with any degree of attention, because they are by far the most conspicuous. The Moon was soon found to run through all its phases, from new till change, in about 30 days; and hence the month, or moon's age, (in Saxon, Mon-ath.) The Sun also was found to change its place among the fixed stars: those which appeared in the west after sunset, after a while appeared in the

east before sunrise, as if this luminary had moved from west to east. By following these apparent changes of position, it was found that the Sun completed the circuit of the ecliptic, or circle of this apparent motion, and returned to the point whence it set out, in about twelve months, in which period the cycle of the seasons was completed. By this means, it was found that the year consisted of about 360 days. More continued and accurate observation showed that it consisted of about 365 days; and the honor of this discovery was claimed by the Egyptians. As the stars could not be seen when very near the sun, the length of the year was ascertained by noticing the time when a certain star near the ecliptic was seen to rise immediately after sunset, and counting from this until it occupied the same position with respect to the sun next year.

Another method was, ascertaining the time of the solstice with a gnomon, and counting the number of days thence till the next solstice. The gnomon was merely a vertical rod, fastened in a horizontal plane, on which was drawn a meridian, or north and south line, running through the foot of the rod. The day of the solstice was known by the fact that the shadow of the rod was then shortest at noon. By comparing the length of the shadow with that of the rod, they could ascertain the sun's meridian altitude; and such instruments were used for this purpose until the 17th century.

The Egyptians added the five additional days after the last month, every year, in order to prevent the various months from rapidly receding among the seasons. But it was gradually found that even this was insufficient. It appeared that the Sun performed its circuit in the ecliptic in about 365 days and one quarter. Hence the months actually receded, so that one fell on the time formerly occupied by the succeeding month in about 120 years. Or more accurately, any particular day, such as new-year's day, would pass through every part of the seasons in 1461 years: for 1461 multiplied by 365, is equal to 1460 multiplied by 3654. This method was actually adopted by the Egyptians, who called the period of 1461 years a Sothic cycle, from Soth, their name for Sirius, or the dog-star. They fixed on this luminary to mark the period, because the Nile began to rise when Sirius rose immediately before the sun.

The Egyptian reckoning did not correspond with the actual changes of the Moon, which occur in less than 30 days; and as it was much easier to determine its exact position than that of a fixed star, it was thought desirable by the Greeks to adopt a reckoning which should conform to the Moon's motions. This they attempted by making the months 29 and 30 days alternately.

This gave a year of only 354 days; and various devices were. employed to obviate the difficulty, none of which proved satisfactory till the time of Meton, the Athenian, who introduced the cycle called by his name, B.C. 432. In 19 years, there are 235 lunar months or lunations, wanting only 74 hours, and 6940 days, wanting 9 hours. Hence if the 19 years were divided into 235 months, which agreed with the changes of the Moon, the same succession of lunar phenomena would again recur very nearly. In order to this, the months of 30 days (called full months) and those of 29 days (called hollow months) were distributed in a rather complex way, so that, in the cycle, there were 125 of the former and 110 of the latter. This cycle is still used for, determining the time of Easter.

The cycle of Meton was improved by Calippus of Cyzicus (B.C. 330,) who proposed to deduct a day from one of the full months at the end of 76 years, hence termed the Calippic period. This very nearly corrected the error arising from the defective hours, in the plan of Meton.

The earliest calendar of the Romans was designed to be lunisolar, like that of the Greeks; but it was very rude and inaccurate. The year was divided into ten months, March, April, May, June, Quintilis (Fifth), Sextilis (Sixth), September, October, November and December." It began in March, and contained only 304 days. This calendar was reformed at a very early period in the history of Rome by the addition of January to the beginning, and February to the end of the year. This arrangement was changed by the Decemvirs (B.C. 452,) who placed February after January. The months consisted of 29 and 30 days alternately, to correspond with the synodic revolutions of the moon. This gave 354 days, and one was added to make it odd, as odd numbers were reckoned more lucky. To make this arrangement correspond with the solar year, it was ordered that a month should be intercalated between the 23rd and 24th of February every second year, to consist of 23 and 24 days alternately. Had this plan been followed, it would give the year a mean length of 365 days, and the months would have corresponded with the seasons for many centuries. But the pontiffs exercised a discretionary power over the intercalary month, and frequently altered its assigned length, in order to hasten or retard election day. This practice produced great confusion; and by the time of Julius Caesar, March had advanced to the winter solstice. When Cæsar, therefore, became dictator, be brought to Rome Sosigenes, an astronomer of Alexandria, in order to reform the calendar. Under his direction, it was ordered that the civil year should be regulated solely by the sun. The common year was to consist of 36 days; but every

fourth year was to contain 366. . The odd months were to contain 31 days, and the even, 30, except February, which was to contain 29 days in common years, and 30 every fourth or leap year. This additional day was intercalated between the 24th and 25th; and as the Romans called the 24th of February, the sixth before the calends or first of March, leap year was called bis-sextilis (twicesixth,) as the 24th was reckoned twice. The new calendar went into operation on the first day of January, B.C. 45, which was called the year of confusion, as 90 days were added to it, in order to brign the computed period of the seasons to correspond with the real.

This new calendar was found to be so superior to all methods which regarded the motions of the Moon, that it superseded every other throughout Europe. It has undergone few changes till the present day; and some of these were not for the better. Quintilis was called July, in honor of Julius Cæsar; and Sextilis was soon afterwards called August, in honor of his successor, the emperor Augustus. As it was considered disreputable to this dignitary that the month named after him should be shorter than that called by the name of his grand-uncle, a day was taken from February and added to July, making the length of these months such as we now reckon, and the length of the subsequent months were changed.* One great improvement which was made soon after the fall of Paganism, in the fourth century, was the abolition of the awkward Roman method of counting backward. The calends, nones and ides disappeared; and the simple and primitive method of counting the days forward, in regular numerical order, was substituted in their place. The intercalary day in leap year was added at the end of February, instead of counting the 24th twice. No further change was made until the end of the sixteenth century.

SECTION II.

Oldest Theory of the World--Superseded by that of a Revolving Celestial SphereAristotle first proves the globular form of the Earth-Its circumference is first measured by Eratosthenes.

THE apparent diurnal motion of all the heavenly bodies, around an immovable point, termed the pole, is one of those phenomena which must have been familiar to all observers of the heavens from the earliest times. The revolving bodies were observed to move so as to be equidistant from the pole, throughout their course. The oldest theory explained this by supposing that the bodies moved eastward under ground, the Earth being assumed

* September and November were made short, and October and December long.