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The cemented joints of the various pieces are ½ inch wide; they are then sewn by a machine, with three seams made with fine silk in the double or threefold material, and four rows of stitches in the fourfold material.

These joints or seams are then covered, outside and inside, with a strip of single silk 1⅕ inches wide, cemented on with a special varnish recently discovered by M. Lachambre.

The strips cemented by this new process have the double advantage of rendering the seams impermeable and restoring to the joints the resistance of which the stitching deprives them.

The varnish used for this cementing meets all requirements; it preserves the natural suppleness of the material, is unaffected by the balloon varnish, which has linseed oil for its basis, and is proof against water and changes of temperature.

The tests made with the joints thus constituted, proved that their resistance was greater than that of the adjoining parts, and Andrée, who only desires an equal strength throughout, naturally was very well satisfied with this result.