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.

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    Crosleys Improved Ventilator for Chimney Tops. NOW KNOW YE, that in compliance with the said proviso, I, the said John Crosley, do hereby declare jhat my said Invention consists of an arrangement in the construction of a ventilator or chimney top for better ensuring the egress of smoke and rarified air in exposed situations, which arrangement I effect in the following manner :— 5 Upon the top of the flue or chimney or other channel intended for the egress of the smoke or rarified air, I affix a cylindrical rim in a perpendicular position, the diameter of which will be ascertained by the size of the flue, chimney, or other channel to which it is attached, and its height may be about one half of its diameter; around and to the top of this cylindrical rim is affixed an inverted 10 frustum of a cone, the smaller diameter of which is of course defined by that of the rim to which it is joined, and the diameter of the upper or widest part is about two fifths larger than the lesser diameter, the perpendicular depth about three tenths of the lesser diameter, and the depth of the side about one third of the lesser diameter; over this is a concave cap or cover whose diameter may be 15 about one third larger than that of the cylindrical rim, and its depth about one fifth of its own diameter, having an aperture in the centre of it about one half of its diameter; to the outer circumference or border of which cap or cover is attached an inverted frustum of a cone, the lower or smallest diameter of which is just sufficient to admit of its being passed down close over the frustum of a 20 cone already secured to the cylindrical rim; its perpendicular depth, and the depth of its side being of the same dimensions as those of the first-mentioned frustum. This concave cap or cover, with the inverted frustum of a cone attached to it, may then be passed down over the frustum of a cone fixed to the cylindrical rim, until the bases of the twTo inverted frustums are brought 25 nearly to the same level; it is then secured in that position by pillars or stays rivetted or otherwise attached, one end to the cylindrical rim, and the other to the concave cap or cover; around the aperture in the centre of the cap or cover already mentioned another cylindrical rim is affixed in a perpendicular position, the height of which may be about one fifth of its own diameter; over this 30 another cancave cap or cover, the diameter of which may be about three fourths of the one first mentioned, and its depth about one fourth of its own diameter, is supported by pillars or stays, as before, at such a height as to bring the circum¬ ference or border thereof a little below the level of the top of the last-mentioned cylindrical rim. The object of this arrangement is to prevent any gust or gale 3f> of wind blowing horizontally across the top of the flue or chimney, and thereby obstructing the egress of the smoke or rarified air. And I do hereby declare that the nature of my said Invention, and the manner in which the same is to be performed, are also particularly described and ascertained in and by