KEAPEES. 743 BEBEC. jointed to the main frame in such a manner that it could be lifted over obstructions. In 1856 Aultman & Miller patented a machine which contained practically all of the essential features of the successful modern mower, viz. two driv- ing wheels (the best types of modern reapers have one), the flexible cutter bar, with rapidly reciprocating blades, having smooth-edge sec- tions, which was so hinged to the main frame that it could be raised and folded over against the latter when the macliine was not in use. While combined reapers and mowers are still made, separate machines for the two purposes are considered preferable. The modern reaper has been adapted to the harvesting of all crops, such as maize, rice, peas, etc., and modified to meet all sorts of conditions, and has enormously decreased the labor involved in har- vesting. Consult: Ardrey, American Agricul- tural Implements (Chicago, 1894) ; Stephens, The Book of the Farm, vol. ii. (Edinburgh and London, 1871); Scott, Texthook of Farm Engi- neei-ing (London, 1885) ; Swift. Who Invented the Reaper? (Chicago, 1895) : Stabler, Overlooked Pages of Reaper History (ib., 1897) ; Official Ret- rospective Exhibit of the Development of Bar- vesting Machinery at the Paris Exposition, 1900, United States Department of Agriculture Office of Experiment Stations, Bulletin 103, BEAR-ADMIKAL. See Admiral. REAR GUARD. A detail of troops assigned to the duty of protecting the baggage and rear of a column on the march. Rear guards are prac- tically advance guards reversed, and are used to protect a force advancing against or retreating before an enemy. In the former case they pro l"l '— — — ^,^R ESERVE .— ■ ONE PI ^-rnfiMT t ^^'r Ain-AiM 4 2* SUPPORT one: section ^^ LIEUTENANT REA R PA RTY ONE SECTION ^B 1'-' SERGEANT ISO YARDS 150 YARDS . «-
- °4
•* 4 REAR POINT REAE GIARU tect the rear of the column against 'attacks by guerrillas (q.v.), partisans of the enemy, or other marauders, and prevent straggling. The most important as well as most difficult duty, however, is when covering and protecting a column m retreat, in which case the rear guard is subject to incessant attack. To organize speedily an effective rear guard out of troops demoralized by defeat is a crucial test of both officers and men. Coolness, courage, and absolute discipline are demanded of the men, while resourcefulness and tactical skill in the officer commanding must be second only to his bravery. Under ordinary con- ditions the distance of a rear guard from the main body is about the same as that of an ad- vance guard (q,v.). At night the distance is considerably lessened. The ever-present danger with a rear guard is the danger of being turned, and to guard against this flanking patrols are sent out to reconnoitre and patrol the flanks. Every available method and opportunity is taken to delay the pursuing force; bridges and roads are destroyed, passages or defiles blockaded, fords rendered difficult of passage, crops destroyed, and liorses and wagons removed. Whenever possible, the rear guard consists of all three arms, and particularly of cavalry, the strength of the guard varying according to the circumstances of the case. The diagram shown is a theoretical disposi- tion of a rear guard consisting of a couipany of infantry. 100 men. REAR HORSE. See Mantis. REASON. See Ratiocination ; Understand- ing. REATJMTTR, ra'6'mur', Ren6 Antoine Fer- chault de (1US3-1757J. A French naturalist and physicist, born in La Rochelle, Feb- ruary 28". 1683. He was educated in the Jesuits' College at Poitiers and at Bourges, and in 1703 he went to Paris^ where he continued the study of physics and mathematics. His earliest publi- cations w-ere mathematical and obtained him an election to the Academic des Sciences in 1708. He then interested himself in the study of ma- rine animals; he proved the power of regenera- tion in crustaceans, studied locomotion in star- fishes, showed that zoophytes were animals, studied the action of the electrical organ of tor- pedo and the phosphorescence of marine ani- mals. In 1710 he began to compile a large work for the Government, Description de divers arts et metiers. Somewhat later a series of important memoirs on the production of steel and on im- provements in the manufacture of iron won him a yearly pension of 12,000 livres. He discovered the method of tinning iron; studied the produc- tion of fine porcelain; also the condition of forests, mines, auriferous rivers, and the fossil beds of France. He invented the Reaumur ther- mometer, in which for the first time the zero- point was made to coincide with the freezing- point. (See Thermometer.) Amid all these ac- tivities Reaumur was constantly carrying on his investigations in the field of natural history. The most important of all his publications are his works in this department ; of these the great- est is Memoires pour serrir d. I'histoire des in- sectes (6 vols., 1737-1748). He left materials for a history of quadrui)eds and birds afterwards made use of by Brisson and Buffon. REBEC (OF. rebec, rebeke. Fr, rebec, from Ar. rabab. rebec, from rabba. to be master). A three-stringed instrument played with a bow. It was of Indian origin, and from Persia it was carried to Arabia, Northern Africa, and, about the eighth century, by the Saracens into Spain. It was in outline like the mandolin, shaped like the half of a pear, with a long neck, finished by
