18 
It was in Guisborough that alum 
was first manufactured in England ; 
and the following is a correct account 
of its introduction into this coun- 
try. Sir Thomas Chaloner, ia his tra- 
vels on the continent, visited the 
Pope’s alum-works in Italy, and, hav- 
ing ascertained that alum might be 
obtained on his own estate at Guisbo- 
rough, he engaged some of the Pope’s 
workmen to accompany him to Eng- 
land, and for that purpose he conveyed 
them on-board a vessel in large casks. 
With the assistance of these workmen, 
he began an alum-work in Belman- 
bank, near Guisborough, which was 
the first in Great Britain. The manu- 
facture at Belman-bank began about 
1595, or soon after, and was carried 
on there for about fifteen years, and 
then removed to another rock at some 
distance, which afterwards was also 
abandoned. ‘The works were begun 
in another place in 1766, and finally 
laid down about nineteen years ago. 
—— 
To the Editor of the Monthly Magazine. 
SIR, 
OUR correspondent, Dr. Forster, 
has noticed in the Meteorological 
Report, (in your Magazine for June 
last, page 459,) that ‘‘ the primroses 
and polyanthuses are numerously de- 
stroyed by some hitherto undiscovered 
animal, which bites them clean off, just 
below the calyx.” This circumstance 
having attracted my notice for the first 
time this season, I was induced to pay 
attention to the subject, and discovered 
the sparrows in the act of destroying 
the flowers of the polyanthus as above 
described. Finding the mutilated 
flowers in many instances torn from 
the calyx, I was led to suppose that the 
germen at the base of the petal was 
sought for by the sparrows as food; 
but, as some of the flowers were unin- 
jured, perhaps the supposition was 
incorrect. 
I have only to remark, that the 
sparrows have been mure mischievous 
this season in the gardens in my 
neighbourhood than on former occa- 
sions. May not this be attributed to a 
scarcity of some peculiar food on 
which they subsist? J.H.E. 
Portsea; June 18. 
—Z 
To the Editor of the Monthly Magazine. 
SIR, 
HE readiness with which you 
é admit any communication rela- 
tive to the useful arts, encourages me 
Polyanthuses destroyed by Swallows.—Improved Bridge. [Aug.1, 
to submit to the public, through the 
medium of your valuable miscellany, 
the following mode of constructing 
bridges. The plan, although not in 
every particular different from those 
existing, may be deemed sufficiently 
so to justify insertion. 
Supposing abutments to be placed 
100 or 120 feet asunder, let A repre- 
sent massive chains, properly secured 
on each, and rendered as tight as ma- 
chinery and the material will admit of; 
over these are placed cross irons of the 
necessary form to sustain the road. As 
it is probable the chains may in some 
measure belly, let B represent side- 
pieces connected, for the purpose of 
enclosing sufficient earth, rubbish, &e. 
to render the roadway horizontal, 
which, with the balustrade, will com- 
plete the structure. A thin iron facing, 
in the form of an arch, will consider- 
ably improve the general appearance, 
and render it similar to that of a light 
and elegant stone bridge. 
When compared with the suspen- 
sion bridges erecting, the principal 
advantages appear to consist in an 
abridgment of the quantity of material, 
(there being no necessity to raise the 
abutments higher than the roadway, 
and perpendicular suspending chains 
being dispensed with,) and a decided 
superiority of appearance, besides — 
consequent saving in labour. 
The contraction and expansion of 
the iron will cause little or no inconve- 
nicnce; the only alteration in either 
case will be a trifling disarrangement 
of the road, (even this is improbable,) 
which, by being M‘Adamised, compe be 
scarcely perceptible. 
The idea suggested itself priae to 
the knowledge of the existence of sus- 
pension-bridges, an inspection of which 
induced me to abandon for the time 
the intention of troubling you with the 
present communication, on the ground 
of its similarity. On a 
the 
