A cell of this kind can easily be made, and to make it the proper size a sheet of zinc 8-1/2 in. long and 6 in. wide will be required.  This zinc is rolled into a cylinder 2-1/2-in. in diameter.  This will allow for a lap of 5/8 in., which is tightly soldered only on the outside of the seam.  Close one end of the cylinder by soldering a disk of zinc over it, making a watertight receptacle.  All soldering should be done on the outside and none of the solder allowed to run on the inside of the seam.  All seams on the inside should be painted with asphaltum in order to cover any particles of solder.  Do not paint any surface, only the joints.  Secure three carbon rods 1/2- in. in diameter and 6 in. long which are copper plated.  Carbons used in arc lamps will do.  File the rods to remove the copper plate, leaving about 1/2-in. of the plate at one end.  Tie the three rods in a close bundle with the copper-plated ends together and make a contact with each rod by soldering a wire to the plated ends, allowing one end of the wire to project about 2 in. for a connection.  The plated ends of the carbons should be covered with paraffin for about 1 in.  This is done by immersing them in a dish of smoking hot melted paraffin until the pores are thoroughly saturated.

The salts for filling are 1/4 lb. zinc oxide, 1 lb. sal ammoniac, 3/4 lb. plaster of paris, 1/4 lb. chloride of zinc mixed into a paste by adding 1/2 pt. of water.  Form a 1/2-in. layer of paste in the bottom of the cylinder and place the ends of the carbon rods on this with their plated ends up.  Hold the rods in the center of the cylinder and put the paste in around the rods with a stick.  Pack the paste in, closely filling the cylinder to within 3/4 in. of the top.  This space at the top is filled with a mixture of 1/2 lb. of rosin and 2 oz. beeswax melted together.  This wax seals the cell and prevents any evaporation.  Connection is made to the zinc by soldering a wire to the outside of the cylinder.

** How to Paraffin Wire [161]

The following description of how to make an apparatus with which to paraffin wire as needed makes clear a method of construction that is simple and easy to put together in a. short time.

Secure a pan to be used for this purpose only; one that will hold about 1 qt.  The details of the construction are given in the diagram, in which P is the pan; B is a base of 1 in. pine; S is the spool of wire supported near one end of the base by nailing on standards H and H; F is a spool, with narrow flanges, supported near the bottom of the pan by the standards T and T. These may be made of two short pieces of a roller fitted into the holes bored in the base; A is a block of l-in. pine with a piece of leather tacked on one side.  Four nails should be driven in the base just outside of the edge of the pan to keep it from sliding off the pan.