356 
THE FLORAL WORLD AND GARDEN GUIDE. 
price. A really good mat, if held by the four corner. 3 , ought to hold 
water for a considerable time without its soaking through, but even 
the “best Archangel” mats of this description are few. Mats, 
however, are expensive, troublesome, and littery, and when shabby 
they are shabby indeed. The price of good mats will average about 
a guinea per dozen ; and supposing each mat to cover three square 
yards, that fixes the price at 7d. per yard, or, as double mats must 
be used, at Is. 2d. per yard annually. Frigi-domo maybe compared 
to a poor blanket ; it is a good non-conducting substance, but thin, 
and 1 fear not very durable — but still, I should think, as good as 
mats. Now, it is an established fact, that confined air is an excel- 
lent non-conductor, and hence a covering, to be really effective, 
should be as nearly as can be air-proof, and, of course, at the same 
time, it will be waterproof. Hence, acting upon this hypothesis, 
some nine years back, I had waterproof covers prepared for all the 
pits and frames under my charge ; these were made of sail cloth, of 
which several qualities were offered by the dealers ; in width it was 
something less than a yard, and the expense, at that time, some- 
thing like Is. 3d. per yard. This was made up by a sail-maker in 
cloths of a size suitable for the pits to be covered, allowing six or 
nine inches to hang over at the back and front of the pits, and being 
elevated about two inches above the glass, and fastened tightly down, 
it became both air-tight and waterproof ; each cover was fastened 
at one end to a roller, and the other end was fastened to the frame 
of the pit, and at the time for covering up nothing more was neces- 
sary than to roll the cloth on and fasten it down by strong strings 
to staples back and front fixed for the purpose ; and hence, “ Let 
the storm pelt us ” or not, we could retire for the night certain that 
everything so protected was safe from frost. These covers, with a 
coat of boiled oil every alternate autumn, lasted for seven years. 
Of course such a covering in the first outset will be more expensive 
than mats or other temporary appliances, but the first expense is the 
last for seven years, and consequently the saving is considerable. 
With proper care, and applied only to their legitimate purpose, I 
believe such covers would last several years longer than mine did, 
and perhaps with some preparation of gutta percha they might be 
rendered still more durable. But my covers were used for all kinds 
of purposes, such as shading seed-beds or cuttings in the open 
ground in the summer, protecting strawberry beds when in fruit 
from drenching rain, sheltering plants in temporary frames, harvest- 
ing seeds, and sometimes protecting the hay-ricks in catching 
harvest weather ; and this last was the most destructive use of all, 
for the heat caused the oil to liquefy, and hence a good deal of it 
was lost. For shading during the summer months thin straw mats 
made with tar-twine, or still better, where they can be procured, 
reed mats, are very useful, as they may be made sufficiently thin to 
shade the plants without obstructing much light ; but possibly good 
screens, or hexagon netting, would be still less expensive, and cer- 
tainly preferable, and more convenient for use. 
For purposes of protection I look upon it to be of as much 
importance to have a waterproof covering as one capable of prevent- 
