System engineering

HAPPY 4TH OF JULY! Jonathan Fields, Josh Burgess and Glen Whelan at the new Deansgrange factory in County Dublin So your minds don't turn to mush over the 4th weekend I've invited Gary Hamilton to share his thoughts on System Cross-Vent tenon extensions. With his applied science and engineering background, he understands and can explain "Systemology" better than anyone I've met. Gary: I wish Charles Peterson had keep a detailed notebook on his design thoughts and theory, etc.  That sure would have helped!  I also hope (as a CPG) none of the thoughts below are taken as blasphemy, I just tend to think about things and the concept of “how and why” always tend to work their way into the thought process.  After all, I do smoke the “Thinking Man’s Pipe”! In PPN #208 Mark mentioned that the screw-in tenon extension first appeared in 1891 and was associated with the stems for the Deluxe and Premier System pipes [see also PPN #154].  When I look at the 1896 catalog, for the stems that have been identified as the ones having the bone extensions, the illustrations do not show any semblance of cross vents being present.  Even with a 120 degree separation for 3 cross vents, one could have easily been illustrated.  But I do not see one. Mark, is there definitive evidence that the cross vents were part of the initial offering of the screw in bone tenon extension in 1891?  What about original patent drawing filings, do any Patent drawings show the presence of the cross vents – or was the tenon extension not a part of patent filings?  I believe that later catalogs like the 1906 used actual photographs of the pipes, and not hand drawn illustrations.  Do any of these later catalogs show the cross vents in the screw-in type tenon extension?  It just seems odd that with as much hand-drawn detail that is present in the 1896 catalog illustrations, that the cross vents were omitted, assuming that they were present at the time to have been illustrated. The only illustration of tenons in the 1906 catalog (also notice the great explanation of stem nomenclature). Mark: No, I don’t see any cross vents in the 1896 nor the 1906 or 1937 catalogs. The patent for the System that Charles Peterson took out don’t mention the tenon extensions. More’s the pity. The 1890 patent wasn't entered in the US until 1894. Here is the complete document. Gary: Here is where my theory starts, and I’ve attached some illustrations to use in the discussion (Figures 1-6). My basic premise is that the original bone tenon extension did not have cross vents and that they came along at some later date.  But when? Let’s start with the following “givens” for the basis of my premise: The screw-in bone tenon extension (later aluminum) extends past (below) the draft hole in the mortise. Fig. 6 The molded tenon extensions, for the most part, do not extend below the draft hole in the…