Specification of John Crosley : ventilator for chimney tops.

  • Crosley, John
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: Specification of John Crosley : ventilator for chimney tops. Source: Wellcome Collection.

    7/8 (page 3)
    Crosleys Improved Ventilator for Chimney Tops. the Drawings hereunto annexed, and the following description thereof (that is to say):— Upon the top of the flue or chimney, or other channel intended for the egress of the smoke or rarified air, I affix in a perpendicular position a cylindrical 5 rim G, G, described in Figures 1 and 2, the diameter of which will be ascer¬ tained by the flue, chimney, or other channel to which it is affixed, and its height may be about one half its diameter; around and to the top of this rim G, G, is affixed an inverted frustum of a cone H, H, the smaller diameter of which is defined by that of the rim G, G, to which it is attached; and the 10 diameter of the upper or widest part is about two fifths larger than the lesser diameter, and its perpendicular depth about three tenths of the lesser diameter, and the depth of the side about one third of such lesser diameter; over this is a concave cap or cover J, J, the diameter of which may be about one third larger than the diameter of the rim G, G, and its depth about one fifth of its 15 own diameter, having an aperture in the centre of it about one half of its diameter. To the outer circumference or border of this cap or cover is attached an inverted frustum of a cone K, K, the lower or smallest diameter of which must be just sufficient to pass over the frustum of a cone II, H, as closely as possible; its perpendicular depth and the depth of its side being of the same 20 dimensions as those of the frustum H, H. This cap or cover J, J, K, K, may then be passed down over the frustum H, H, until the bases of the two inverted frustums H, H, and K, K, are brought nearly to the same level. It is then secured in that position by small pillars or stays I, I, rivitted or otherwise attached, one end to the cylindrical rim G, G, and the other to the cap or 25 cover J, J ; around the aperture in the centre of the cap or cover J, J, another cylindrical rim L, L, of the same diameter as the aperture, is affixed in a perpen¬ dicular position, the length of which may be about one fifth of its own diameter; over this another concave cap or cover N, N, N, the diameter of which may be about three fourths of the cap or cover J, J, and its depth about one fourth 30 of its own diameter, is supported by pillars or stays M, M, at such a height as to bring1 the outer circumference or border thereof a little below the level of the top of the rim L, L, so that no gust of wind can pass directly across through the upper part of the flue or chimney, while sufficient space is left open for the egress of the smoke and rarified air. The red dotted lines in Figure 1 are 35 intended to shew the course by which the smoke and rarified air make their escape; and Figure 3 is merely a shaded elevation of the contrivance when complete, and ready to be affixed to the flue or chimney. I do not mean or intend hereby to limit myself to the employment of any particular material or materials in the construction of the several parts described, but to avail myself