By introducing a more refined calculation with logarithms, the height would have been about 10 or 12 feet more, though it is obtained at considerable risk of error, from errors either in the ordinary tables, or oversights in the steps of the calculation, which to unpractised persons fréquently occur; whereas the foregoing requires only a very simple arithmetical computation, where no figure of real utility is suppressed, which is frequently done, to make the operation look simpler than it really is.

EXAMPLE II.

On the 12th of September 1829, the following observations were made with Mr Adie's sympiesometer.

At Edinburgh, 270 feet above the sea.

S'

272 fathoms, and t = 57° 7 Fahrenheit;

At the top of Allermuir, on the same day,

S490 fathoms, and t 50°-3 Fahrenheit;

ť =

Hence S-S'490-272

218 fathoms;

And t+t' 57°·7 +50°•3 = 108°, which, from the engraved scale on the instrument, gives the factor m == 1.053;

Whence 218 x 1·053 229.5 fathoms, or 1377 feet.

If to this, 270 feet be added, for the height of the lower station, at Edinburgh, above the sea, we shall have 1647 feet for the height of Allermuir, above mean-tide at Leith. This exceeds the former by about 43 feet, which must be partly ascribed to the unfavourable state of the weather at the time, and partly to a small error in the foregoing formula. On the whole, I consider the mean of these results, or 1625 feet, to be nearly the true height, as I have found it from other observations.

EXAMPLE III.

In the month of August 1830, with a mountain-barometer of the best construction, the following observations were made at

Fort-William, and on the top of Ben Nevis, to determine its

A small quantity in so considerable a height, considering the

simplicity of the last method.

As the weather was unfavourable, and the barometer changeable, with only one observer, who took the observations, first, at the bottom in the morning, then at the top about mid-day, and again at the bottom in the evening,-of which the mean of the first and last was reckoned the true height of the mercurial column at the bottom, there might have been some error arising from this cause. As the barometer continued to rise somewhat gradually, the error from this source must likely be small. At all events, whatever error attends the use of the one instrument likewise affects the other, since they accord so well when used together with equal care.

I have likewise calculated the height of Ben Nevis more rigorously by employing logarithms, and using the dew-points, besides other refinements, which would, increase the height to about 4430 feet. As this exceeds all the heights I have ever met with attributed to it by at least 50 feet, I cannot say what confidence is to be placed in it, more especially, as I have been informed the Ordnance Surveyors make it only about 4360 feet, or 70 feet less. From the great distances of their stations, a very slight error in the angle of elevation, arising from the variable nature of terrestrial refraction, will produce a considerable error in their results in feet. Indeed, according to Mr B. Bevan's paper in the Philosophical Transactions for 1823, Part I., there are errors in the altitudes of some of the stations in England, of from 50 to 100 feet, in heights of between 700 and 900 feet! In this case I cannot what confidence may be placed in that of Ben Nevis, though, in our measurement of Benlomond, the correspondence was as close as could be desired.

say

From the present measurements, too, it appears that the sympiesometer is an instrument which, when in good order, may be confidently trusted as giving results, when carefully used, very near the truth. The formula now investigated, appears to give results rather too small by about one-hundredth of the whole, and this is the reason why those by the sympiesometer seem to be, on comparison, too great. If one-hundredth of the height by the formula be added to itself, the final result would agree very closely with the logarithmic process.

54. SOUTH BRIDGE, EDINBURGH.

On the Luxury of the Romans.

THE Roman writers who flourished during the Republic say little about Natural History. It is more treated of by the writers under the Empire. But the works they have left us on such subjects contain few original remarks, and are little else than compilations, a circumstance which must appear very strange, since no nation had ever greater opportunities of observing.

In the earliest ages of the republic, besides that the Roman institutions were in general adverse to every kind of study, the simplicity of manners that prevailed was especially unfavourable to the progress of natural history, a science of luxury, expensive, and not to be carried on without many previous arrange

ments.

Indeed the relations among the beings that form the subject of natural history, cannot be established without bringing together a great number. Much assistance is therefore derived from commerce, drawing, as it does, towards a central point, the productions of foreign countries. Now, the Romans, during a very long period were not commercial. By the first treaty made with the Carthaginians, they bound themselves not to sail beyond the strait that separates Sicily from Africa. Still later, in the year of Rome 405, they gave up altogether their trade with Sardinia, and with the coast of Africa.

Commerce was checked, not through ignorance, but from the policy of their government, in order to withstand the introduction of luxury. Rome had no silver money till the 472d year from the foundation of the city, 268 years before Christ. At the date of the last Macedonian War, a senator was degraded from his rank for having ten pounds of silver plate. Gold plate was seen for the first time at the end of this war, in the triumph of Paulus Æmilius. But luxury was the speedy consequence of victory, and the luxury of individuals was carried to the utmost extravagance. We shall notice it in so far as regards natural history.

.

The luxury of the table, for example, caused to be imported into Rome from foreign countries a multitude of animals; of OCTOBER-DECEMBER 1830.

D

which several had no other recommendation but rarity, and being excessively dear.

The luxury of dress also is interesting, with respect to precious stones and dyes. That of buildings, on account of the marbles brought from different parts of Italy, from Greece, and even from Gaul. And the luxury of furniture is interesting, from the valuable woods employed.

Of the Luxury of the Table.

Quadrupeds.-During the second Punic War, Fulvius Hirpinus devised the mode of retaining quadrupeds in parks. These parks were named Leporaria, because three sorts of hares were reared in them, the common hare, the original Spanish rabbit, and the variegated or alpine hare, a species now almost entirely destroyed. In like manner, nearly all the native animals of our forests were bred in these parks, besides the wild sheep and the mouflon. These animals were almost domesticated, and were taught to unite at a signal. One day, when Hortensius was entertaining his friends at dinner in one of his parks, at the sound of a trumpet, stags, goats, and wild boars were seen running up, and gathered round his tent, to the no small dismay of some of the guests. Servius Rullus was the first who had a whole boar served on his table. Anthony, during his triumvirate, displayed eight at one feast. The Romans considered as a great delicacy the grey dormouse, a little animal that dwells in the woods, and in the holes of oak trees. They reared them in enclosures, and lodged them in jars of earthen-ware, of a particular form, fattening them with worms and chesnuts.

Birds. Lenius Strabo of Brundusium invented aviaries for confining such birds, destined for the table, as could not be kept within the walls of a poultry-yard. It is he, says Pliny, that taught us to imprison animals whose abode is the sky. Alexander had introduced peacocks into Greece, where they were regarded only as objects of curiosity. Hortensius was the first who had one served at a banquet, when he was appointed to the office of augur.

These birds soon multiplied, and Ptolemy Phocion was astonished at the great number of them he found in Rome. Aufidius Lucro made about L. 600 a-year by fattening peacocks.