But, before he ventures to fow this plant, let him remember, that, where it is once established, it will hardly fail to spread through the adjoining fields, and can hardly ever afterwards be thoroughly rooted out.

I have often imagined, that this kind of fence might be greatly improved, both in beauty and ftrength, by planting a row of ivy plants beneath the firft course of feal in building the dike, which would, in a short time, climb up the fides of the dike, and cover the whole with a close and beautiful network of woody fibres, covered with leaves of the most beautiful verdure, which would tend to preferve the dike from being eat away by froft, and other viciffitudes of weather.

*It is generally allowed, that all the phænomena produced by what we call froft, are entirely occafioned by a certain degree of cold; and that, of confequence, if we by any means exclude the cold, we effectually guard against the effects of froft. If this is the cafe, we would naturally expect, that those

things

weather.

top,

And, when it arrived at the it would there send out a number of strong woody branches, forming a fort of hedge, that would afford fome fhelter to the fields, and break the force of the wind confiderably; but, as I never yet had an opportunity of trying the experiment, I only here offer it as a probable conjecture. I have seen a garden wall, that had been built of ftone and clay, ornamented and strengthen

ed

things alone would preferve other objects from the effects of frost, that did most powerfully exclude the cold; yet, it is found by experience, that a very thin covering of straw, or other small and light vegetable twigs, carelessly ftrewed upon any thing, prevents the effects of froft in a much more powerful manner than almost any kind of folid covering of much greater depth, even where it is fo clofe all around as to exclude all accefs to the air. I leave this phænomenon to be accounted for by naturalifts; and would only here remark, that, from repeated obfervations, I am pretty certain of the fact; from which I conclude, that the leaves of the ivy would powerfully preserve the wall from the effects of frost.

ed in this way. I have had the experience of ivy growing very well upon a dry stonedike; and have likewise seen it growing up the walls, and covering whole cottages built of feal, which have, by this means, been preserved intire long after other naked walls of the fame kind have fallen to decay. But, not having had plants of this kind at hand, I have not had an opportunity of trying it in the manner proposed; although, I think, there is the greatest reason to hope for fuccefs *

§ IV.

* Since writing the above, I have met with Dr Hafslequift's voyages, who defcribes, in the highest terms of rapture, the beautiful appearance of the garden-walls all around Smyrna entirely covered with ivy. He does not specify the materials of which thefe walls are compofed, but, it is probable, they may be various. His obfervations, at least, fhow the practicability of what I have recommended. Ivy may be propagated by cuttings; but, it is probable, that they would require to be well rooted in garden mould before they were planted out for good.

§ IV.

Of white Thorn-Hedges.

THE fences before mentioned may be employed upon particular occafions; but, in general, hedges must be confidered as of much greater value, and therefore, with juftice, demand a more particular fhare of our attention and care.

Many plants have been fuccessfully employed for hedging; but, among these, the common white thorn is juftly esteemed the most valuable in this country, as it poffeffes, in a more eminent degree than any other plant common with us, the requifite qualities of quickness of growth, ftrength, pricklinefs, durability, and beauty. It will, therefore, be proper to make fome remarks upon the method of training this valuable plant, before I take notice of any other.

§ V.

Of the most eligible Method of planting these.

IT may, in general, be remarked, that a hedge of thorns which has been planted in the face of a ditch, thrives better than when planted in any other way; and that, on the contrary, this plant almost never thrives fo ill, as when put upon the top of a bank faced with ftones. This laft method, therefore, ought to be avoided as much as may be; and the first be practised in all cafes where it can conveniently be done,

Of those who practise this method of planting a hedge, fome plant only one row of thorns, while others prefer a double, and others even a triple row, placed at different heights in the face of the bank; putting the plants in each of these rows opposite to the interstices of the other rows.

the double or triple rows are

But, as either

attended with

the