PEARL 



4543 



PEARY 



effective remedy for leaf spot. Fire blight, the 

 most serious menace of the prosperity of the 

 pear industry, turns the leaves and blossoms 

 black, and if allowed to go unchecked will at- 

 tack even the wood and bark. In such cases a 

 sticky substance oozes out from the bark, that 

 may be carried by insects to other trees and 

 so spread the disease. The most satisfactory 

 method of combating fire blight consists in 

 pruning suspected twigs and branches during 

 the winter. Wounds must be sterilized with 

 sublimate, and pruning tools, which 

 be a source of contagion, should also be 

 thoroughly sterilized after each operation. A 

 "clean up" at the right time may save an en- 

 tire orchard. 



Food Value. Fresh pears have a high per- 

 ige of water 84.4 per cent and contain 

 14.1 per cent of carbohydrates and small 

 amounts of protein and fat (see articles APPLE, 

 PEACH. PUM, for comparison of values). They 

 ::ot only wholesome and laxative, but their 

 juiciness and delightful flavor make them an 

 >n. Dried pears have a carbohy- 

 drate content of 72.9 per cent, and the canned 

 fruit, of eighteen per cent, "^hether eaten fresh, 

 or canned, preserved, baked or otherwise cooked, 

 pears are perennially a favorite food. M.W. 



Consult Brackett's "The Pear, and How to 

 Grow It." In United States Department of Agrrl- 



< -nit . s linlh tin 482; Bartrum's Book of 



s and Plums. 



PEARL, purl, a small, lustrous drop of shelly 

 substance, produced by oysters, clams and other 

 mollusks. Pearls are of many hues, from sil- 

 -white to black, and all have a satiny sheen. 

 The explanation of their formation is one of 

 most interesting facts in nature. The 

 smooth, iridescent lining seen on the inside of 

 a mollusk shell is the secretion of the animal 

 within. It sometimes happens that a grain of 

 sand, the egg of some minute sea animal or 

 other substance becomes lodged inside the shell, 

 the soft body of the occupant. In 

 order to avoid this irritation of its delicate 

 body, the animal proceeds to cover the object 

 with layers of mother-of-pearl, and in so doing 

 it may produce a gem of grca Round or 



pear-shaped pearls entirely deta< . the 



;nrt highly prised. The largest 

 known pearl is in the Victoria and Albert 

 seum, in London. It is four and one-half inches 

 m cirnimiVi-.-nce and weighs three ounces. 



i- the birthstone for June. 

 From the< mes pearls have bcr i . 



in jewelry, and many romantic stories have 



been told of individual pearls of great rarity. 

 Perhaps the most familiar is the account of 

 Cleopatra's having swallowed a gem that would 

 now be valued at $300,000 or $400,000 (see, also, 

 subhead Some Famous Gems, in the article 

 GEMS). Romance, too, has been woven about 

 the business of diving for pearls, largely, no 

 doubt, because of the peril involved. The pearl 

 .ystor lives at a depth of from eight to tw. 

 fathoms, and is found in the greatest numbers 

 in the channels dividing groups of islands, where 

 there is a strong, dredging current. The diver 

 goes to the bottom armed with a net of rope 

 for scooping up the shells. In shallower water, 

 where the pressure is not so great, a diver may 

 remain at the bottom for as long as two hours. 

 The shells so collected are unloaded from boats 

 on the sand and allowed to lie until the mol- 

 lusks have decomposed. They are then washed 

 in sea water, and the hunt for gems begins. 



Fisheries. The chief fisheries are to be found 

 in the Persian Gulf, among the Polynesian 

 Islands, in the Sulu Archipelago, along tin 

 northern and western coasts of Australia and 

 off the coast of Lower California. The Persian 

 Gulf is particularly famous for its fine pearls. 

 but Australia has become no mean rival in re- 

 cent years. The Mississippi River and its tribu- 

 taries furnish fresh-water pearls of considerable 

 value, and the mussel shells arc much in de- 

 mand for the making of buttons, knife handles 

 and other articles of commerce. Muscat ine. 

 Iowa, is the center of this industry. Imitation 

 pearls are cleverly executed in many parts of 

 the world. G.BJ>. 



Consult Kunz and Stevenson's Hook of the 

 Pearl: Kunz's Pearls and Pearl Fisheries of th< 

 United States. 



Related s-.iiijfciH. The reader Is referred to 

 the following articles in these volumes : 

 Birthstones Mother-of- Pearl 



Gems Muscatlne. Iowa 



Mollusks Oyster 



PEARY, ROBERT EDWIN (1856- ), an 

 American Arctic e lie undisputed dis- 



coverer of the North Pole. He was born at 

 Cresson, Pa., educated at Bowdoin College, and 

 became a civil engineer in the United States 

 navy. From 1884 to 1888 he was employed in 

 . ys of the projected Nicaragua Canal, at 

 first as assistant engineer and later as chief. A 

 age to Greenland, with a trip into the inte- 

 rested him in Arctic research, and in 

 1891 he set out in charge of an expedition 



most important geographical kn<>\vl 

 gained from his explorations was the fact th.it 



