12 Retrospective Vieio of the 



rience on the new plan. In several instances around Boston, 

 where gutters have been introduced, from some negligence in 

 their construction, or the employment of inferior materials, 

 the system has failed altogether : but as the only complaint 

 was the leakage of the gutters, it is apparent that the fault 

 was not with the system, but with the apparatus. 



Another new system has very recently been discussed in 

 the Gardeners'' Chronicle : it is called the Polmaise method, 

 and is said to answer every purpose. The system consists in 

 the introduction of hot air, passed through a heated chamber, 

 and from thence into the house, where after it becomes cool, is 

 conducted back through open gutters beneath the walks, thus 

 keeping up a continued circulation of air. It has always ap- 

 peared to us that some such plan might be made to answer 

 the purpose : but as theory will not always answer, experi- 

 ments are necessary to test the advantages of a new method. 



In England a great deal has been written within the last 

 ten years on the proper form and construction of boilers, so 

 as to save the greatest amount of heat. This has resulted in 

 the general use of conical boilers, and more recently the im- 

 proved one of Burbidge & Healy. Each of them have their 

 advocates, and they are both undoubtedly good. Boilers of 

 similar form and construction would be preferable to the flat 

 ones now in use in our greenhouses ; and if iron ones of the 

 above patterns could be obtained, without the expense of im- 

 portation, they would soon be generally introduced. This 

 subject will occupy our attention. 



Commercial Gardens. 



If we were to judge from the Catalogues which are yearly 

 published, — and some of which might be termed Books, — the 

 nursery business would present a most active condition. Ex- 

 tensive catalogues, however, are not always an indication of 

 this. There is a good demand for trees, and of really thrifty 

 and fine specimens, especially of apples and pears, to a greater 

 extent than the supply. This excess of demand has caused 

 the estalishment of several new nurseries. 



The Pomological Garden of the late Mr. jManning contin- 

 ues in a prosperous condition under the charge of his soil and 



