46 GoDDARD, on an Improved Mounting Table, 
so that tlie glass slide is supported by two ridges of thin 
metal. 
The construction of the tables before us is the same. The 
smaller is intended to be used with an ordinary lamp^ and 
made of thin brass (fig. 1). The largest is to be heated 
by a spirit lamp, and consequently much more substantial. 
It consists of a plate of brass 12 inches by 3 and l-|^th of 
an inch thick ; upon this two pieces of metal of the same 
thickness, and 12 inches by 1, are rivetted, leaving a clear 
space 1 inch wide in the centre of the plate ; the whole being 
supported on tubular legs 7 or 8 inches high (fig. 2.) By 
means of the flat surface in the centre of the table, a great 
amount of heat is obtained by radiation ; the thickness of 
the side pieces allows a current of air to pass between the 
slide and the hot metal, so that direct heat is avoided, and 
the object to be mounted does not come in contact with the 
hot surface. The use of metal one inch wide has this advant- 
age — two inches of the glass are strongly heated, and though 
that material is a bad conductor, sufficient is conveyed to the 
centre of the slide for the purpose required. 
By changing the position of the lamp, or by regulating 
the flame, the operator can obtain exactly the degree of heat 
he requires. 
By the assistance of this apparatus I have prepared the 
accompanying slides, the whole process of mounting, harden- 
ing, cleaning, and finishing being completed in one evening ; 
the most delicate algse, such as Delleseria alata^ Plocani- 
cum coccineum, Plilota pluniosa, Ceramium rubeum, and even 
the Cladophora, retaining their colour, though mounted in 
Canada balsaam. 
