21. An idea appears to prevail in some quarters that the occupation of the Park is intended to be of a permanent, and not, as has been repeatedly announced, of a merely temporary character, and the Commissioners are given to understand that by proposing to construct a building into which a good deal of brickwork is to enter, they have shown an intention at variance with their professions. Upon this point they have to remark, in the first place, that, although the eminent architects and engineers whom they have consulted, and to whom they have uniformly given instructions to prepare plans suitable to a temporary structure, have agreed to recommend the use of brick and other durable materials, they have left it perfectly open to contractors to send in their tenders for the execution of the work in any material or materials whatsoever, and have notified their readiness to entertain such tenders, on the single condition of their being "accompanied by working-drawings and specifications, and fully priced bills of quantities." It is probable that some such tenders will be made, and if made they will be impartially considered; but the Commissioners must protest against the supposition that it is necessarily more judicious to construct a temporary building of perishable than of enduring materials. The first requisite of the building is, that it should be suitable for its purpose, capable of protecting the valuable goods deposited in it from injury of every kind--as, for instance, from the weather, from the effects of the dampness of the soil, from the danger of fire, and so forth, and that it should be strong enough to avert all risk of accidental damage. Its next requisite is, that it should be economical, and in estimating its cost regard must be had not only to the expense of erection, but to the facility of removal and the value of the materials when removed, as a building may easily be conceived to be cheaper which should cost 100,000_l._ to erect, but of which the materials could afterwards be sold for 50,000_l._, than another would be which cost but 80,000_l._ in the first instance, but of which the materials should become so far deteriorated as to produce only 20,000_l._ when taken down. It is the opinion of those who have devised the plans in the present case, that a building constructed of durable materials will in the end be cheaper than one constructed of such as are more perishable; particularly as a considerable portion of the building, namely, the iron roofing, will be of a kind which is generally used in the construction of railway-stations, and will probably be disposed of for that purpose after the close of the Exhibition, as its temporary application to the purposes of the Exhibition will be of no detriment to its being so. An opportunity of testing the correctness of this opinion will be given when the tenders