My dog, the astronomer

 "Every man desires to live long, but no man wishes to be old." - Jonathan Swift

I was recently out with the dog one final time prior to getting her settled for the night and going to bed myself.  As always, she was sniffing every square inch of the enclosure for unusual odors, and gazing off into the woods for any sign of movement.  Because a very cold air mass has moved into the region, the normal winter overcast is gone, and the sky was very clear and very dark.

The dog suddenly froze for several seconds and stared at something up in the sky.  It was Jupiter.  I've never seen a dog stop what they were doing to inspect a planet in the night sky before - it was pretty cute.  Siberian Huskies, derived from the extinct Russian Taimyr wolf, are highly intelligent, and they are very observant animals.  They also have a strong prey drive, which is why she never seems to overlook anything that is different in her environment.  Great family member!

I was out in the shop for the first time in a while, and happened to go into the air compressor room.  The air compressor reservoir was at zero pressure, and the motor wouldn't start :(  After a few seconds, I figured maybe try the reset on the motor.  It clicked and the compressor started to run!  

However, as it thumped for several minutes building pressure, I wondered why it the motor overload had tripped in the first place.  Once it reached full pressure and the compressor shut off, I figured out why:  There was air hissing out from somewhere up top.  It took a little while to find it, but eventually I located the leak. 

The pressure switch that turns on the air compressor has a tiny air line attached, and inside a small brass sleeve sits a bellows (or a piston).  This bellows expands (or piston moves), and when the air pressure reaches a certain point a rod presses down and shuts off the compressor motor.  Once it retracts enough due to loss of pressure, the motor starts again.  The bellows (or piston) developed a leak and the air compressor apparently started and stopped enough to trip the overload on the motor.

Below:  Inside the center brass cylinder is a bellows.  Air is leaking out the mouse-hole at the bottom right of the brass cylinder.   The lower brass device is an over-pressure safety valve.

I have a new pressure control switch on order from Amazon.  It cost about $17.  Hopefully the fittings will work out correctly and the switch works as intended with easy to adjust start/stop pressure setpoints.

Of more importance, I purchased a new man-toy.  This is a 1918 Stromberg-Carlson Model 896 wall-mount telephone.  Everyone should have one of these.  The only drawback to this phone is that it isn't quarter-sawn oak :(  

 Below:  Old-growth quarter-sawn oak, courtesy voorheescraftsman.com

But overlooking the cut of the wood the phone is complete and in working condition!  Crank the handle and the ringer starts whacking the bells.

I have no plans to connect it to a telephone system, so don't much need the wiring diagram, but it's nice to have it.

The microphone mouthpiece is chipped and the threads are chowdered out to the point where the mouthpiece simply falls out.  I have a replacement on order though.

I'll polish the metal and hang it somewhere in the shop.  If it weren't for cell phones and the new WiFi router out in the shop, I might have taken time to get it hooked up and working.  If there's ever a high-altitude Electromagnetic Pulse or another Carrington event, this thing is probably hardy enough to survive.  

But mostly I just picked it up because it looks pretty cool.