OBOE 



mo 



OBSIDIAN 



Protein Total 



Weight cal- cal- 



Measure Oz. ories ories 



Broiled steak, piece 3 In. across 3.0 70 150 

 Scalloped potatoes, 1 cup 



(scant) >.- 13 150 



Buttered beets, & cup 2.0 50 



Lettuce and tomato salad. 1 



serving W 6 200 



SaJted almonds, 1 2 nuts 0.5 13 



Boiled custard, % cup 3.3 20 150 



The normal weight for a man five feet tall 

 is from 126 to 140 pounds; for a woman it is 

 from 107 to 120 pounds. For a man five feet 

 inches tall it is from 145 to 154 pounds, 

 and for a woman, from 137 to 147 pounds. A 

 man five feet ten inches should weigh from 

 168 to 175 pounds, and a woman, from 164 to 

 170 pounds. By comparing your weight with 

 the average that most nearly corresponds to 

 your height, you can tell whether you are too 

 corpulent or too thin. 



Related Subjects. The reader is referred to 



the following articles in these volumes : 

 Calorie Fat 



Carbohydrates Food 



Diet Health Habits 



Digestion Proteins 



OBOE, o'bo, a wood-wind musical instru- 

 ment much used in modern orchestras to pro- 

 duce plaintive and wailing effects. Its note is 

 mild, but penetrating, and can be greatly swelled 

 or decreased, giving a wide variety of expres- 



THE OBOE 



sion. The oboe is made in three pieces, usu- 

 ally of boxwood, ebony or rosewood, and con- 

 sists of a tube about twenty-one inches long, 

 tapering from a narrow mouthpiece at one end 

 to a bell-shaped opening at the other. A 

 smaller brass tube containing a reed extends 

 through the instrument, and in its upper and 

 middle sections are holes which the performer 

 opens or stops with his fingers. The oboe has 

 a range of nearly three octaves. In its sim- 

 plest form it was known to the ancients and 

 may be seen in Egyptian and Grecian sculp- 

 ture. The name oboe is from the Italian. The 

 instrument is sometimes called hautboy, from 

 two French words haul, meaning high, and 

 bois, meaning wood and refers to the high 

 notes produced by the instrument. 



OBSERVATORY, obzer'vatori, an institu- 

 tion or building supplied with instruments used 

 in observing and studying meteorological and 

 astronomical phenomena. Observation and 



study of astronomical phenomena are as old 

 as human history, but the first observatory 

 built for the purpose was that erected in Nu- 

 remberg by Bernard Walther in 1472. 



A modern observatory is equipped with a 

 telescope fitted with a spectroscope and photo- 

 graph apparatus, transit instruments, meridian 

 circles, sidereal and common clocks and chro- 

 nometers, magnetic apparatus and instruments 

 for making charts. The telescope is sheltered 

 by a dome, which can be revolved so that its 

 opening may point to any part of the heavens. 

 The foundation upon which the telescope rests 

 is deep and solid, since the least tremor seri- 

 ously interferes with the observer's work. 



Among modern observatories, the Greenwich 

 Observatory in England, founded by Charles 

 II, holds the most important position. It is 

 equipped with the latest and most reliable 

 scientific instruments. Throughout England 

 and the northern part of Europe time is regu- 

 lated by signal from Greenwich Observatory. 

 In the United States the Naval Observatory at 

 Washington performs the same function. In 

 the United States great scientific progress has 

 been made within recent years, and the ob- 

 servatories are well equipped and under the 

 direction of scientists of high standing. The 

 Harvard University Observatory, the United 

 States Naval Observatory at Washington, the 

 Lick Observatory of the University of Califor- 

 nia and the Yerkes Observatory belonging to 

 the University of Chicago and situated at Lake 

 Geneva, Wis., are among the most important 

 of the world's observatories. The Canadian 

 Dominion Observatory is at Ottawa. 



Related Subjects. The reader is referred to 

 the following articles in these volumes : 

 Astronomy Time 



Lick Observatory Weather Bureau 



Telescope Yerkes Observatory 



OBSID'IAN, natural glass thrown out in 

 heated condition by volcanoes, its glassy ap- 

 pearance being caused by sudden cooling. It 

 contains about the same substances that are 

 found in ordinary glass, but is usually black. 

 Sometimes the presence of iron causes it to 

 turn a rusty brown on the surface. Obsidian 

 is very hard and brittle, and cannot be drilled 

 and blasted like other rock. Obsidian Cliff, in 

 Yellowstone National Park, is a mountain of 

 glass, and is the largest mass of obsidian known. 

 The road at the foot of this cliff was con- 

 structed by making fires on the rock, then 

 breaking it by dashing cold water on it while 

 it was hot. 



