288 Securities against Fire, &c. 
States, in order to communicate their knowledge to such persons 
here, as may be depended upon, to apply it to use when required. 
Whatever expense may be incurred in doing this, must fall short of 
the amount of the value put in Boston, upon a single picture, not 
yet exhibited, as well as of the sums actually paid or pledged for a 
single statue in several great cities of the U. States. 
3. It is known that feather-beds, elastic cushions, and sometimes 
straw, notwithstanding its combustibility, have been placed in front 
of houses in flames, in order to receive persons who might ven- 
ture to leap upon them from the upper apartments; but nothing of 
this kind seems in any degree so promising, as what has been call- 
ed a stretched sheet ; the invention of which is attributed to an Eng- 
lishman of the name of Wecks; the plan being stated to be as fol- 
lows. A sheet is provided, in the borders of which large hoop-holes 
are left all round; in which holes, persons standing below (passen- 
gers and others) place their hands, in order to grasp the sheet firmly, 
and keep it extended. Hence, when the party leaping down from 
above strikes the sheet, the following results may naturally be ex- 
pected. Ist. The holders of the sheet will drop it a little, in conse- 
quence of their slackening their hands, as soon as the weight of the 
descending person is felt. 2nd. The sheet is lowered farther, from 
the stretching given to the threads of which the sheet is compos- 
ed. 3d. The sheet suffers a new depression, when the form of its 
surface, which at first resembles the cavity of the section of a hol- 
low sphere turned with the open part upwards, is made to ap- 
proach that of the horizontal section of the apex of a hollow 
cone also turned upwards. Each of these principles adding to the 
effect in diminishing the impulse of the descending weight, so as 
to make it gradual, the leap becomes harmless.—Accordingly, 
when an exhibition of the operation of this sheet was made in 
Southwark (which is considered as a part of London,) in the pres- 
ence of numerous spectators; among whom were some officers of 
the London Police who may be said to have been there, professional- 
ly; various persons leaped upon the sheet, one after the other, 
from the elevated parts of a house; and all reached the ground with- 
out accident. 
The statement of this exhibition has probably not reached the U. 
States upon any other than newspaper authority ; but as the case is 
recent, it may easily be inquired into; and, in the mean time, it is 
open to new experiments in this country. If the matter be substan- 
