index - a numerical scale used to compare variables with one another or with some reference number. 1  margin of error, margin of safety, safety margin - the margin required in order to insure safety; in engineering the margin of safety is the strength of the material minus the anticipated stress.
Nutty Ways to Celebrate Squirrel Appreciation Day This Year. SQUIRRELS! Whether you love them or loathe them, National Squirrel Appreciation Day, January 21st, is a great time to take a few moments and learn about these nutty animals. If you count flying squirrels we have 10 tree species in North America.
Spend the day watching Rocky and Bullwinkle episodes. Cheer for Rocky! Visit the Web site of Christy Hargrove, a wildlife rehabilitator in North Carolina who is the originator of Squirrel Appreciation Day (see link below).