Related:

• I will not squeak chalk.
• Skinner: Oh oh. Two independent thought alarms in one day.
  The students are overstimulated. Willie!...
• You're not gonna believe this. I saw a murder. I got there five minutes after it happened.
  Apparently, from what I saw, the body fell onto a chalk line exactly the same shape....
• Manually operated analog scribing device (description of chalk)
• The chalk marks are transient, the formulas eternal. -- S. Weinstei
• Measure with a micrometer. Mark with chalk. Cut with an axe.