Dean of Norwich, well known for his valuable writings;-particularly the Connection, &c. and the Life of Mahomet. It is written on vellum; and on a blank leaf of the book is the following account of its con

tents:

Hic codex in linguâ Perfica et metricè confcrip'tus eft; continetque ampliffimum corpus hiftoriæ ve'terum Perfarum ufque ad Mahommadifmum. Poteft ⚫ autem dividi in tres partes, quorum prima narrat vitas 'et gefta illorum regum qui paulo poft diluvium ufque ad Cyrum et Hyftafpem duraverunt. Secunda 'defcribit fequentes reges ufque ad Alexandrum magnum, de quo multa narrat quorum apud Græcos Latinofque autores nulla ne vel minima eft mentio, ubi de bellis Caidi et Pori, regum Jndiæ tractatur. Porus autem vocatur FUR, rex Canugi, id eft Gangis. 'Etiam longus eft fermo de amoribus Alexandri cum Roxanâ, qua Raufehaak appellatur. Hæc autem

fecunda pars clauditur uno capite, in quo mentio fummatim fit de omnibus regibus qui Perfidem tenuerunt ab Alexandro Magno ufque ad tempus • Alexandri Severi. Tertia, denique, pars continet vitas regum Saffanidarum, ufque ad Jeidægerdum 'ultimum regem Perficæ ex religione Magorum, qui 'victus eft à Mahome- danis, aliquot annis poft Hegiram, regnante Omaro II. Califa.

Autor autem hujus tam grandis operis eft Haffan * Ebu Scharaf, cognomine Fordauffi; id eft, ParadiС fiacus; natus in urbe Tus Perfiæ, omnium apud Perfas poetarum facile princeps. Dedicavit vero fuum opus Mahmudo Sobachtino, regi Gafnazidarum, in cujus, laudes plura hinc inde capita impendit, Vocatur hoc poema, Schahnama, id eft Hiftoria Regum; cujus tamen duæ primæ partes, fi ' ad veritatem exigantur, potius dicendæ funt fabulæ nenfes, quam veræ hiftorice. At tertia eft 'utiliffima, vitas Saffanidarum regum hiftoriæ narrat, quorum exigua admodum eft mentio apud Græcos Latinofque

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Latinofque autores, qui poft Alexandrum Severum • floruerunt.

'Confulatur Harbolitus in vocibus Fordoffi, Mahmud Sobochtehin et Schanamah; ut cognofcatur ' vero ætas autoris, et quod ad eum pertinet.'

In the fame repofitory is a valuable collection of original letters.

The following from fir William Waller, the great leader of the parliament army (as it appears to have been written in confequence of a confidential letter from fir Robert [afterwards lord] Hopton) is equally remarkable for its elegance and spirit: for the urbanity of the gentleman, and the steadiness of the hero. The letter admirably exemplifies a very juft remark of Jackson in one of his Thirty Letters, That when mer fpoke from their real feelings, the language of the last and the prefent century hath been nearly the fame. To my noble friend, fir Robert Hopton, at Wales. * Bath, June 16, 1643.

• Sir, The experience I have had of your worth, and the happiness I have enjoyed in your friendship are wounding confiderations, when I look upon the prefent diftance between us. Certainly my affections to you are fo unchangeable, that hoftility itself cannot violate my friendship to your perfon; but I must be true to the caufe wherein I ferve. The old limitation, Ufque ad Aras, holds ftill; and where my confcience is interested all other obligations are fwallowed

up.

I fhould most gladly wait upon you, according to your defire; but that I look on you, engaged as you are in that party, beyond a poffibility of retreat; and confequently incapable of being wrought upon by any perfuafions, and I know the conference would never be fo close between us, but that it would take fire, and dishonour. receive a conftruction to my

That great God, who is the fearcher of my heart, knows with what reluctance I go upon this fervice;

*A fhort time before the great battle of Lanfdowne.

and

and with what a perfect hatred I deteft a war without an enemy. But I look upon it as Opus Domini, and that is enough to filence all paffion in me.

The God of Peace, in his good time fend us peace: and in the mean time fit us to receive it!

We are both on the ftage; and must act the parts that are affigned us in this tragedy.

Let us do it in a way of honour, and without perfonal animofities :-but, whatever be the iffue, I fhall not willingly relinquish the dear title of

Your affectionate friend, and faithful fervant,

"W. WALLER.'

ART. IX.

Defcription de l'Aeroftate l'Academie de Dijon, &c. Le tout Extrait du Compte rendu à cette Societe

par

M.

M. de Morveau, Chaffier et Bertrand. Printed at Dijon, 1784. 8vo. 224 pages, with four engrav ings.

TH

HERE has been a time when the surprise and wonder of aërial voyagers, with a detail of their feelings at the elevation of a mile and a half above the furface of the earth, and a minute account of the aftonishment and acclamations of the populace, on their fafe arrival, was received as good philofophical news. But that day may now be faid to be paft. Numberless projects refpecting air balloons have already funk into oblivion, and the feeble repeaters of the original experiment are followed only by the vulgar. If the experiments fpoken of in the prefent work had been of this nature, we fhould have readily paffed them in filence, notwithstanding the refpectable authorities that are held forth in the title page; but,

as

as they are, on the contrary, fuch as, in many refpects, do honour to the undertakers, we fhall with pleasure proceed to give an abstract of its contents.

The work is not confined to a particular account of the conftruction and exhibition of the aëroftate made at Dijon. Three fourths of the book confifts of inftructions, or, if it may be fo termed, theory, founded on chemical experiments, and reafoning partly deduced from the received principles of mechanics, and partly from actual trials. The whole treatife is comprized under four general parts or divifions, relating to the enveloppe, or matter forming the balloon; the gas, or inflamable air deftined to fill it; the methods of directing its courfe; and the particular detail of the proceedings at Dijon with the aeroftate which is the fubject of the piece.

The gentlemen confine their attention to balloons that contain inflammable air, in which proceeding they are chiefly actuated by the confideration that the bulk of these is lefs with a given buoyancy than it can be in the Mongolfiers. For, as they obferve, fince the difficulty of rowing a boat through the air would be inconfiderable, even against the wind, if it were poffible to be done, without at the fame time oppofing fa large a refifting furface as the balloon prefents to the air; it must follow that a fmaller balloon ought to have the preference. But we muft here take the liberty to obferve that the gentlemen are in an error with regard to their eftimate of the comparative refiftance of balloons of different magnitudes, in pages 9 and 138; for the refiftance does not encrease in the ratio of the buoyancy, which follows the bulk, but only in the ratio of the power thereof.

2

In the confideration of the materials proper to form a balloon that fhall be fufficiently light, and at the fame time impermeable to the gas, our authors have made a calculation of the weight of a globe of tin of a line in thickness, and fifty feet in diameter, which they

they find to be about 4000lb. without reckoning the foldering, and indifpenfible reinforcements. This laft particular is of fo much importance, that we think it no prefumption to affirm that it affords the highest probability of rendering the fcheme abortive. For it is certainly very difficult to imagine, and, perhaps impoffible to execute, any piece of mechanism that fhall enable a globe of fuch a magnitude, of such a thickness, and of fuch a weight, to preferve its figure fo accurately as to remain air-tight, without at the fame time loading it with an apparatus that would entirely defeat the original purpose. This objection feems to be likewife of confiderable weight against the propofed globe of pafteboard. The experiments relating to the method of filling inflexible globes are ingenious and interesting.

The conftruction of the actual balloon of taffeta is defcribed at large, together with the method of making and applying an excellent varnish, adopted after fucceffive trials, with more than thirty different compofitions, made in the laboratory of the academy. It confifts of a mixture of bird lime, made from the inner bark of holy-oak, with linfeed oil, previously faturated with litharge. The proportions, the precautions required in making and applying it, and its advantages over the folution of the elaftic gum of Cayen are minutely ftated, but cannot be here given, without injuring the matter by too much brevity. In the course of their experiments, our authors found that the mutual action between the included inflammable air, and the fatty covering, tended exceedingly to vitiate the former. This fact may, perhaps, in fome meafure, account for the fuppofed efcape of inflammable air from balloons, which have by their continued inflation been imagined to be fupplied in a ftrange manner with common air, in proportion as the lighter gas leaked out. Several carious obfervations concerning the heat and deterioration of common air included in their balloon, when exposed to the fun, are given in

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