1906] BRIEFER ARTICLES 213 
The aluminum shells here figured (fig. 2) are designed to provide light, neat, 
clean, and easily applied covers for pots on this principle. Flower pots are 
now made so nearly in standard sizes that it is possible to make the shells to 
fit them closely, and shells will be made for the present in 3-inch, 34-inch, 
4-inch and 5-inch sizes. To hold the rubber roof tightly to the shell, a 
tightly-fitting band or strap of aluminum, resting in a groove just below the 
strengthened top of the shell, may be drawn to any desired tightness by a 
convenient screw-nut, shown (though dimly) on the right in the figure. The 
rubber roof may be attached to the plant in any of the ways ordinarily used, 
but I find upon the whole the best method to be the following. In the 
middle of a proper-sized piece of medium-thick rubber-sheeting, a hole a 
little smaller than the stem of the plant is made with a cork-borer, and a cut 
is made with scissors from this to the margin of the piece. It is then placed 
around the stem, the cut edges of the central hole are stretched to overlap 
a little, sealed together with rubber cement and held clasped until this sets. 
Then a line of the cement is run to the margin, sealing one edge over the 
other. When fully set, the margin of the rubber is clasped to the shell, 
all surplus material is cut away, and a very neat and perfectly tight roof 
temains.—W. F. GANonG, Smith College, Northampton, Mass. 
