Today was a warm, sunny day, so I went rock collecting.  Some friends are moving soon, so they are letting me collect a lot of spare rocks and boulders (mainly 100-200 pounders) for my future projects.  I have at least two this year to complete.  I use a tree mover, a wheeled device, to move the rocks up a ramp to my truck bed.  Over the past 46 years, I collected over 10,000 rocks from various places nearby.  And, yes, I did count them!  The only cost was in my time and effort.  My lot has a lot of slopes, so I have many terraces and walls using rocks.  Hauling all those rocks is probably one reason why I am ten 10 pounds lighter than I was 50 years ago.  It also helps to explain why I have had two hernias and 11 surgeries on various joints over the years!  I do not believe I should waste any part of my body, so when I die I want to be completely used up.  I estimate I am 78.55% there.
   As stated earlier, I have a lot of rocks with moss growing on them, over 600.  Recently I have been attaching moss to rocks using 100 percent silicone caulk.  The moss soon spreads over the rock, attaching itself with anchoring devices called rhizoids.  These do not deliver water or nutrients to the mosses, as mosses have no vascular systems (though a few have a primitive delivery system, but far less efficient than those of more advanced flowering plants).