On the Glazing of Hot-houses. 297 
However satisfied Mr. Saul may be with a theoretical knowledge of 
the system he proposes to notice, we beg to say, we are fully convinced 
his covers over the joints of the glass, whether of metal or other material, 
are very objectionable, and productive of injury. 
Several years ago we had some sashes glazed in this way; and in order 
to get the edges of the metal to bed close to the glass, as well as to have it 
bed down to the tops of the squares of glass, and also to admit of folding 
back for the purpose of any required re-glazing, we were obliged to have 
the metal very thin, but we uniformly found that the edges were raised 
by the action of the sun upon them during summer ; this caused a sepa- 
ration of the putty or white lead, from either the metal or the glass, 
generally the latter. Such openings admitted and retained the wet in 
winter, which being expanded by frost, forced the openins^s still wider. 
This plan was also found very expensive in its first construction, as well 
as in repairing injuries every spring, by bedding and re-puttying the 
metal covers. 
We had also a number of sashes constructed with a piece of metal' 
much stronger than the above, and which would not rise at its edges; this 
mode also proved objectionable, for when the piece of metal was long, 
and a square of glass was required putting in, a great deal of trouble was 
caused by having to loosen the covers for the purpose of getting the square 
to its place, also in re-puttying and bedding the metal afterwards. 
The plan of having each piece of metal only the length of the squares 
it had io cover, was also tried. There was less trouble in re-glazing by 
this manner than the former, but it ^yas liable to every other evil attend- 
ing that, as well as some others; and the expense of the method was a 
considerable increase upon the former. 
One of the greatest evils complained of in the old mode of glazing, is 
that of wet getting between the glass and putty ; and this must always be 
the case, in consequence of the ribs svvelling in damp weather, and con- 
tracting in hot weather, putty not being equally affected with the wood ; 
it of course leaves the wood or the glass, and in either case wet finds ad- 
mittance, and a portion of dirt getting washed in between the putty and 
the wood or glass, the putty then loses its effect. Water being thus 
permitted to lodge underneath the putty, or betwixt it and the wood, 
and the air not having free access to dry up the moisture, the putty soon 
loses its properties, and decays. It will then soon, be found that the 
putty at the under side of the glass, and upon which it was bedded, will 
also speedily docav. Thus steam, or rain admitted from broken squares, 
running dov/u the ribs, is permitted to enter, to the detriment of the 
wood, as well as sUowing drips to enter the house. By the expense of 
an annual attention to painting, inside and outside, these evils may in 
some degree be lessened. 
Vol,. }, Ko.7. PP 
