Specification of John Wallace : ships' safety hearth.

  • Wallace, John.
Date:
1857
Catalogue details

Licence: Public Domain Mark

Credit: Specification of John Wallace : ships' safety hearth. Source: Wellcome Collection.

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    Wallaces Improvements in the Safety Hearth. the manner in which the same is to be performed, are particularly described and ascertained in and by the following description thereof, reference being had to the Drawing hereunto annexed, and to the figures and letters marked thereon (that is to say) :— My improvement or improvements in the safety heath consists, first, in 5 applying a smoke jack in the flue or chimney of a safety hearth, and by means of certain other additions hereafter shown and described, forming a ship’s safety hearth capable of roasting meat by the power derived from such smoke jack. . -.x •./. Secondly, in suspending or placing safety hearths on a fixed stand or frame, 10 such framing forming a curved railway, whereby the safety hearth will by its gravity always keep its perpendicular position, even at the time of the ship’s heeling. Thirdly, in a particular application of a damper for the purpose of changing the direction of the heated air and frame. 15 Description of the Drawing. Figure 1 is a front view of a safety hearth, having my improvements applied thereto, and being the principal Figure in the Drawing referred to, I shall be the more^particular in the description of it. It consists of the frame, boilers, and cooking apparatus attached thereto, also a smoke jack for roasting, 20 which jack, although in itself it forms no part of my Invention, I deem it necessary to explain as connected with my safety hearth, in so far as I have introduced it for this purpose. And I have substituted figures instead of letters to denote the particular parts of it, as follows:—In Figure 1, which as well as Figure 3 is supposed to have part of the bulb or cylinder composing the 25 upper part of the flue or chimney removed, in order to shew more clearly the internal construction of the smoke jack. 1, 1, 1, &c., is a horizontal fan, composed of six or more vanes or leaves, attached to an upright axis 2; it occupies the whole internal diameter of the bulb or cylinder, and about one- fourth of the depth of the straight part of it; 2, the upright axis which runs up 30 in the centre of the cylinder, and is driven round by the smoke acting upon the inclined vanes of the fan in its ascent up the flue from the furnace; 3 is a spiral or endless screw cut upon the upright axis 2, which drives a brass cog¬ wheel consisting of about forty teeth, seen in Figure 3; 4 is the axis of this brass wheel, having a pulley near its end, for receiving a chain to turn the 35 spit, and runs in a centre made in the bar 5, which I call the pivot rest, drawn separately in Figure 21 ; 6 is an iron arm, on which several parts o£