Ill. Admin. Code tit. 8 § C
United States Linear Measure
12 inches (in.) = 1 foot (ft.)
3 ft. = yard (yd.) = 36 inches
5½ yards = 1 rod (rd.) = 16½ feet
320 rods = 1 mile (mi.) = 1760 yards = 5,280 feet
Chain Measure (Gunter's or Surveyor's Chain)
7.92 inches = 1 link (li.)
100 li. = 1 chain (ch) = 66 feet
80 ch. = 1 mile (mi)
The engineer's chain is 100 feet long and consists of 100 links of 12 inches each. 52.8 chains = 1 mile.
Square Measure
144 square inches (sq. in.) = 1 square foot (sq. ft.)
9 sq. ft. = 1 sq. yard (sq. yd.)
30¼ sq. yard = 1 square rod (sq. rd.) = 272¼ sq. ft.
160 sq. rd. = 1 acre (a) = 4,840 sq. yd. = 43,560 sq. ft.
Surveyor's Measure
625 square links (sq. li.) = 1 square rod (sq. rd.)
16 sq. rods = 1 square chain (sq. ch.)
10 sq. ch. = 1 acre (a)
640 a. = 1 square mile (sq. mi.)
36 sq. mi. (6 mi. sq.) = 1 township (tp.) = 2,304 a.
Cubic Measure
1728 cubic inches (cu. in.) = 1 cubic foot (cu. ft.)
27 cu. ft. = 1 cubic yard (cu. yd.)
United States Liquid Measure
4 gills (gi) = 1 pint (pt)
2 pt. = 1 quart (qt) = 8 gills
4 qt. = 1 gallon (gal.) = 8 pints = 32 gills
31½ gal. = 1 barrel (bbl) = 126 quarts.
2 bbl. = 1 hogshead (hhd) = 63 gallons = 252 quarts.
Apothecaries' Fluid Measure
60 minims (m.) = 1 fluid dram (fl. dr.)
8 fl. dr. = 1 fluid ounce (fl. oz.) = 480 minims
16 fl. oz. = 1 pint (0) = 128 fl. dr. = 7,680 m.
8 0. = 1 gallon (cong.) = 128 fl. oz. = 1,024 fl. dr.
U. S. Dry Measure
2 pints (pt.) = 1 quart (qt.)
8 qt. = 1 peck (pk) = 16 pints
4 pk. = 1 bushel (bu.) = 32 quarts = 64 pints
105 quarts = 1 barrel (for fruits and vegetables) = 7,056 cubic inches.
Avoirdupois Weight
27 11/32 grains (gr.) = 1 dram (dr.)
16 dr. = 1 ounce (oz.) = 437½ grains
16 oz. = 1 pound (lb.) = 156 drams = 7000 grains
100 lbs. = 1 hundred weight (cwt.) = 1600 ounces
20 cwt. = 1 ton (t.) = 2,000 pounds
Troy Weight
24 grains (gr.) 1 pennyweight (dwt.)
20 dwt. = 1 ounce (oz.) = 480 grains
12 oz. = 1 pound (lb.) = 240 dwt. = 5,760 gr.
Apothecaries' Weight
20 grains (gr.) = scruple
3 scruples = 1 dram = 60 grains
8 drams = 1 ounce = 24 scruples = 480 grains
12 ounces = 1 pound (lb.) = 96 drams = 288 scruples = 5,760 grains
The Metric System
The metric system is based on a unit of length (the meter.). A cubic box one-tenth of a meter on the side has the unit of capacity, a liter, and the water contained in a liter weighs one kilogram. The unit of weight, the gram, in the metric system is the weight of water contained in a cubical box one-hundredth of a meter on a side. (Note: These values are not precisely correct but hold for all but the most refined measurements.)
The entire system is then built up by multiplying or dividing the unit by ten, one hundred and one thousand, using always the same prefix to indicate what the unit is multiplied or divided by, thus:
milli means 1/1000 or divided by 1000
centi means 1/100 or divided by 100
deci means 1/10 or divided by 10
deka means 10 or multiplied by 10
hecto means 100 or multiplied by 100
kilo means 1000 or multiplied by 1000
The tables then become:
Length
10 milli-meters = 1 centi-meter
10 centi-meters = 1 deci-meter
10 deci-meters = 1 meter
10 meters = 1 deka-meter
10 deka-meters = 1 hecto-meter
10 hecto-meters = 1 kilo-meter
Weight
10 milli-grams = 1 centi-gram
10 centi-grams = 1 deci-gram
10 deci-grams = 1 gram
10 grams = 1 deka-gram
10 deka-grams = 1 hecto-gram
10 hecto-grams = 1 kilogram
Capacity
10 milli-liters = 1 centi-liter
10 centi-liters = 1 deci-liter
10 deci-liters = 1 liter (1 cubic deci-meter)
10 liters = 1 deka-liter
10 deka-liters = 1 hecto-liter
10 hecto-liters = 1 kilo-liter
Area
100 sq. meters = 1 are.
100 are. = 1 hectare
100 hectares = 1 sq. kilometer
In the metric system there is but one standard of weight, one standard of measure for liquids and dry commodities alike, and but one standard of length.
Ill. Admin. Code tit. 8, § C