214 PARKS AND PLEASURE-GROrNDS. 



useful bj gentlemen acquiring first notions on the 

 subject, as it is almost wholly tree from technical de- 

 tails. Since these works were published, the system 

 of roofing glass-houses by small glass ridges and fur- 

 rows has been greatly improved by its inventor. Sir 

 Joseph Paxton, and employed in the construction of 

 the Crystal Pakice. which, but for this method of roof- 

 ing, might never have existed in its universally admired 

 form. In our practice in this department of gardening, 

 we have found the ridged roof to be admirably adapted 

 to green-houses, conservatories, and even to the minor 

 structures emploj^ed for the rearing of plants. 



Note. — The "span roof" has been adopted in the 

 United States within the last five years, and in prac- 

 tice, generally approved. Plant, or tree-houses in this 

 style have a showy efiect in pleasure-grounds, and 

 where not interrupted by the shade of adjacent struc- 

 tures or trees, are, as distinct buildings, perhaps the 

 best and most economical. For graperies they possess 

 some advantages over the lean-to method of roofing, 

 admitting the sun from rising to setting, and a greater 

 degree of light than the others will attract.^ — Ed. 



