136 
in bedding; and your’ readers will not 
wonder that his conception was still- 
born, when they are directed to draw 
out the air by an air-pump, and restore 
it by a condenser, adding medicated gases 
at their discretion, The ingenious in- 
ventor never considered, that the cavity 
might be filled by a pair of bellows, and 
emptied by pressure; while substances 
that could confine air would not be 
favourable to the action of his medicated 
gas, Let us examine the matter in a 
practical point of view :— 
1. The substance containing the air 
may be prepared, by the application of 
any varnish employed to make balloons 
gas-tight. A list of these varnishes 
may be found in “ Mackenzie’s Re- 
ceipts,” pp. 58; 59,60. Most of them 
are very troublesome in use, being 
clammy, and requiring much time to 
dry; but this is of less moment, as the 
varnish can be applied to the inside of 
the linen, or other substance used as an 
air-bag. 
2. To prevent the bag from swelling 
into.a globular form, it may be quilted 
in different parts, like a mattrass; or 
may be divided, by internal partitions, 
into several long cavities, distinctly 
filled, and not communicating with each 
other. 
3. The air may be introduced by a 
pair of bellows, closing the mouth of 
the air-bag when we open the bellows. 
It is on this principle that a bladder is 
filled through a pipe; and the entrance 
may in both cases be made safe, by a 
spring tightly applied round it ;—or the 
nozzle of the bellows may centain a 
valve, opening outwards, 
4. The real objection to the plan is 
this :—An air-bed would not allow the 
passage of insensible perspiration, as a 
feather-bed is found to do:—it might 
be sufficiently warm, air being a bad 
conductor of heat.. The inventor would 
probably attempt to meet this objection 
by an increased number of under-blan- 
kets, or by some substance, which will 
confine air, and yet allow the passage of 
aqueous vapour. 
5. There are, however, very nume- 
rous cases to which tlie objection does 
not apply. Compressed air may be used 
for bolsters, sofas, chair-cushions, car- 
riage-seats, &c. Mattrasses so formed 
might occasionally be of great use in 
the army and navy; they could be dried 
like a pair of sheets, and might be sloped, 
to any angle, at the foot, by extending 
the air cavities across them. 
Wherever the principle can be applied, 
there is a great advantage, in economy, 
Air Beds.—Egyptian Antiquities. 
(Mar. 1, 
durability, cleanliness, portability, avoid- 
ance of damp, and, especially, of the 
evaporations from decaying organized 
substances, saturated with unwholesome 
effluvia. . SEPTIMUS. 
—_ re 
for the Monthly Magazine. 
Ecyrrian ANTIQUITIES. 
HE Egyptian Museum at Turin (as 
appears from the letters of M. 
Champollion to the Duke de Blacas 
dAulps) contains a great number of 
antiquities, brought into Europe by M. 
Drovetti, who, in the research and ac- 
quisition of them, has spent twenty years 
in Egypt alone. Some learned mem- 
bers of the Academy of Turin are busily 
employed in preparing for the public 
an account of this inestimable collec- 
tion,—which comprises Egyptian mo- 
numents of all arts, and of almost all 
ages. Through the recommendation of 
the Duke de Blacas, M. de Champol- 
lion (so well known for his discoveries 
in the art of deciphering hieroglyphics, 
and for his noble undertaking of the 
Egyptian Pantheon) has been permitted 
to make researches in this Museum. 
His first letter treats of the most an- 
cient monuments—those which throw 
new light on the history of Egyptian 
arts, and which, applying to the history 
of the end of the seventeenth and com- 
mencement of the eighteenth Egyptian 
dynasty, serve to verify the justness of 
the ideas which the fragments of the 
chronological canon of Manethon have 
transmitted to us concerning these two 
periods. Thus the learned observations 
on Egyptian arts, and the explanation of 
the monuments of this nmseum, which 
relate to the nineteenth century B. C., 
and correctly followed up to the year 
1493 before this same era, form the 
double subject of the important re- 
searches contained in this first letter. 
The chronological notice is enriched 
with other matters, and developes in 
many charts, the chronology of the 
times before mentioned : these go back 
as far as the epoch of Abraham. | 
—————— * 
For the Monthly Magazine. 
JAPANESE ANTIQUITIES.) - 
COMPARISON of Chinese and 
of Hindoo. antiquities with Egyp- 
tian has been already . instituted ;— 
[See M. M.' p. 13, No.406,)—but no 
attempt has yet been made to shew 
the affinities and distinctions between 
the architectural monuments of Egypt 
and of Japan—though Sir T. S. Ratiles, 
and other travellers, have furnished 
ample. 
