The following are conversion factors for old measurement terms that may have been used in the Châteauguay Valley. The old french terms were used in Quebec, Canada and Louisiana, USA. Some modern terms are included for completeness. The units of inches, feet, yards, and miles, unless further qualified, are the English or US units in common use today. The numbers in square brackets [n] indicates the source of the information listed at the bottom of the page. For other terms, see the web links below, especially Russ Rowlett's Dictionary of Units of Measurement.
- The acre is an English unit of measurement used for both lineal distance and area of land. "Acre" is an Old English word meaning a field and was originally defined as the area that could be plowed in a day by a yoke of oxen.
The lineal acre is equal to the length of the side of an area acre or approximately 208 feet.
An area acre is an area of land one furlong (40 rods or 10 chains) long by 4 rods (or 1 chain) wide. Thus an acre is 10 square chains, 160 square rods, 43,560 square feet, 4840 square yards, 1.184 arpent or 0.4047 hectares. There are exactly 640 acres in a square mile. [1,2,6,7]
- Arpent (Arpen)
- The arpent is an old french unit used for both lineal distance and area of land (superficie).
The lineal arpent equals 30 toises or 10 perches; this is about 191.8 feet or 58.47 meters. The unit was used to measure land; in fact, arpentage is the French word for surveying. 
The arpent unit of area measurement (land area or acreage is called superficie in french) is equal to one square arpent. The arpent of area equals 900 square toises, 100 (square) perches, approximately 0.8445 acre, 0.3419 hectare (3419 square meters) or 36,801 English square feet.
- Bushel (British and US)
- A bushel is a measure of dry volume commonly used for the measurement of quantities of grains such as wheat. The old English (or Winchester) bushel is the same as the US Bushel and was officially defined as the volume of a container 18-1/2 inches inside diameter by 8 inches deep. This is a volume of 2150.4 cubic inches, 1.2445 cubic feet, 35.24 liters, 4 pecks, or 32 (dry) quarts.[1,6]
The more recent British Imperial bushel is equal to 1.032 US Bushels. [2,6]
- The chain (Gunter's or Surveyor's Chain) was used for accurate surveys of land. The actual chain was exactly 66 ft long and consisted of 100 links, each 7.92 inches in length. The unit of measurement called a chain equalled 66 feet, 20.1168 meters, 4 rods, or 0.1 furlong. 80 chains equalled 1 mile (often used as a scale on old maps). An area of land 1 chain by 10 chains long equalled 1 acre. [1,6]
- A furlong is an old English unit of length whose name is derived from the Old English word fuhrlang, meaning "the length of a furrow"; it represents the distance a team of oxen could plow without needing a rest. It is equal to 660 feet, 40 rods, 10 chains, 1/8 mile, or 201.17 meters.[1,2,6,7]
- The hectare is the modern metric unit used for measure of land area. It is equal to 10,000 square meters (the area of a square 100 meters on each side), 107,639 square feet, 395.37 square rods, 2.471 acres, or 2.925 arpents. [1,6]
- An old french unit of length (English translation = league). There were a number of different definitions of a lieue, ranging from the 17th century lieue equal to 1666 toise , the 18th century "lieue de poste" or "Lieue de Ponts et Chaussées" equal to 2000 toise (2.422 miles) [6,7] to a "lieu" equal to 10 km (6.24 miles).  In modern metric France, the Lieue is now considered to equal exactly 4 km (2.486 miles).
Marine surveyor's used a lieue equal to 1/25 degree of latitude. This translated to 2.4 nautical miles, 2.762 statute miles or 4.445 km.  The scale on an old map of the Island of Montreal printed in 1744 referred to "Lieue Communes de France de 2282 Toises" which when converted equals 2.768 miles, almost identical to the above 1/25 degree Lieue.  The same map has a second scale labelled "Grandes Lieues de France de 2853 Toises" which converts to 5.560 km (3.456 miles). This length is almost identical to the modern, internationally recognized league of 3 nautical miles (5.556 km or 3.452 miles). 
The seigniories granted by the old French Regime in New France all specified the area in terms of so many "lieues" of frontage (usually on a river) by so many lieues of depth without specifying which lieue was used. Comparing the old records for the Seigniory of Beauharnois which was 6 lieues by 6 lieues to the distances on a modern topo map, showed that it was 20.44 miles wide on the back side or 3.406 miles per lieue. This is close to the 3.456 miles per "Grande Lieue". Other documents state that Beauharnois was 18.3 miles on a side which would not correspond to any of the defined Lieues.  The mystery continues.
- A link is 1/100th of a surveyor's (Gunter's) chain. It is equal to 7.92 inches.[1,2,6,7]
- The livre (English translation = pound) was an old french unit of weight. It was equal to 1.079 pounds or 489.5 grams. 
- The minot was an old french unit of volume measure used for grains such as wheat. The origin of the word is unknown although it also appears as the root of minotier (flour miller) and minoterie (flourmill). In terms of other old french units of volume, the minot was equal to 3 boisseaux or 48 litrons. A boisseau was equal to 16 litrons or approximately 13 liters. A litron was equal to about 0.813 liters. The equivalent in modern units varied over time from 39 liters to 36.3 liters compared to English bushel of 36.37 liters and a US bushel of 35.24 liters. 
- A perche (English translation = rod) is an old french unit of measurement of both length and area (superficie in french). The lineal perche is equal to 18 pieds, 3 toises, 19.183 feet, 5.847 meters, or 0.1 arpent (lineal).
The superficie perche is equal to one square lineal perche, 0.01 arpents (superficie) , 368.0 square feet, 40.89 square yards, 155.33 square meters or 0.01553 hectares. 
- The pied (english translation = foot) is the old french foot. It had various length equivalents including 13.11 inches, 1.09 feet or 0.333 meters in a 1853 document  and an official Canadian equivalent of 12.789 inches, 1.066 feet or 0.3248 meters. 
- A pole is another name for a rod unit of length.[1,6]
- The pouce (English translation = inch or thumb) is a french unit of length. There were 12 pouces to the pied but since the pied had various equivalents at different times, so did the pouce. A 1853 book has it equal to 1.09 inches or 0.0277 meters. The official Canadian rate now would be 1.066 inches or 0.0271 meters
- The quintal is an old french unit of weight. It was used in Quebec for goods such as flour, peas, potatoes, etc. One quintal equaled 100 livres, 48.95 kilograms or 107.9 pounds.
- Rod (Pole)
- The rod is an old English unit of length. The rod supposedly come from the length of the whip used by oxen drivers whose length had to reach to the lead oxen in a 8 oxen team. It is equal to 5.5 yards, 16.5 feet, 1/40th of a furlong, or 5.029 meters. [1,2,6]
- The rood is an old English unit of area measurement. It equalled 40 square rods (poles), 0.25 acres, 10,890 square feet, 1011.7 square meters or 0.10117 Hectare. [1,2,6]
- The toise is an old french unit of length. It was originally introduced in 790AD and represented the distance between the fingertips of a man with outstretched arms, equivalent to the English fathom. Its length may have varied over time but it is considered equal to 6 pieds, 6.395 feet, or 1.949 meters. [1,5,6]
Some Links regarding Conversion Factors and Old Measurement info:
- A Dictionary of Units of Measurement. A listing of just about every imaginable unit, old and new, used in the world. Authored by Russ Rowlett of the University of North Carolina at Chapel Hill, NC.
- Anglo-Saxon Weights and Measures. A very good page of info on the what, why and how of old English measurement.
1/ Templeton's Pocket Companion,2nd Ed., D. Appleton & Co., New York, 1853.
2/ Handbook of Chemistry and Physics,55th Ed., CRC Press, Cleveland,OH 1974
3/ Chemical Engineers' Handbook, 2nd Ed., Edited by John H.Perry, McGraw-Hill Book Co., New York, 1941
4/ Carte de L'Isle de Montreal et de ses Environs, H.Bellin, 1744
5/ Larousse French-English/English-French Dictionary, Unabridged Ed., Larousse, Paris 1993
6/ A Dictionary of Units of Measurement - online.
7/ Jacques Proot (author of the Anglo-Saxon Weights and Measures web site mentioned above).
8/ The History of the County of Huntingdon and of the Seigniories of Chateauguay & Beauharnois, Robt. Sellar, Huntingdon, 1888