Old Cement Sacks

I pulled two of these from the wall above the pocket door tracks and Eric found a few more in a wall in the guest bedroom. They were so caked with soot that they were completely illegible, but an extra long soaking in hot water in the washer made them this legible. BTW- do you catch that 94 POUNDS?! These things are about the size of a rice sack. I'm wagering these were from the pre-OSHA era.