Mechanics for young America; how to build boats, water motors, wind mills, searchlight, electric burglar alarm, ice boat ..etc.; the directions are plain and completeReprinted from Popular mechanics . piece of iron H is held in place by the release A. Now C is a coilof wire from a door bell. R is an armaturewhich works A on pivot J. M is a U-tube,filled with mercury, one end being con-nected to a half liter glass flask F by thetube T, and the other end terminates in anoverflow tube 0. B is a battery of threebichromate cells which are connected upwith the C and the platinum points 1—2,which are
Mechanics for young America; how to build boats, water motors, wind mills, searchlight, electric burglar alarm, ice boat ..etc.; the directions are plain and completeReprinted from Popular mechanics . piece of iron H is held in place by the release A. Now C is a coilof wire from a door bell. R is an armaturewhich works A on pivot J. M is a U-tube,filled with mercury, one end being con-nected to a half liter glass flask F by thetube T, and the other end terminates in anoverflow tube 0. B is a battery of threebichromate cells which are connected upwith the C and the platinum points 1—2,which are fused into the U-tube. On fixing the furnace the iron piece Htakes position X, this being the normal posi-tion when draft door D is closed. On arriv-ing upstairs I pull the cord G, which causesthe piece H to become fixed in the verticalposition by means of A. This opens thedraft door at the same time. Now whenthe furnace heats up sutRciently it causesthe air to expand in F, which causes themercury in M to rise a little above the point2. This immediately causes a current toflow through C which in turn draws Rtowards it, raises A and causes H to drop toposition X. This shuts the furnace 74 POPULAR MECHANICS Now the furnace, of course, cools down, thuscausing the air in F to contract and conse-quently opening the circuit through C. Ifat any time the furnace should overheat,the raising of A, on which is grounded awire from a signal bell upstairs, will makea circuit through the bell by means of thepoint Z and wire leading therefrom. Thisbell also serves to tell me whether H hasdropped or not. This same device of regu-lating the draft D can be used to regulatethe damper, found on the coal doors of mostfurnaces, by simply fusing a platinum pointon the other side of M and changing thecord which is attached to D. A two-contactswitch could also be inserted to throw con-nections from 2 to 3. It would work in thismanner: The damper door, of course, whichkeeps a low fire, would be
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Keywords: ., bookcentury1900, bookdecade1900, bookp, booksubjectindustrialarts
