FLYING SQUIRREL 



2211) 



FOG 



^ 



DIAGRAM OF A ZEPPELIN 



(a) Nine sections showing aluminum girder work under outer fabric cover, and nine of the 

 seventeen chambers, with a hydrogen gas bag In each. (6) Outer fabric cover, concealing the 

 other eight gas chambers, (c) Solid prow, from which the girders radiate, (d) Car, so constructed 

 that it will float on water, (e) Opened part of the passageway between the cars; the entire pas- 

 sageway is always covered, as in (/). 



in diameter. The gas bags of such a model 

 contain 742,000 cubic feet of hydrogen gas. 

 This gas is so much lighter than air that that 

 amount will lift about twenty-one tons of 

 weight into the air. The entire ship and fit- 

 tings weigh about fifteen tons, therefore the 

 Zeppelins can carry several tons in crew, fuel 

 and supplies. 



A non-rigid dirigible has no framework to 

 maintain its shape; if its gas contracts, air is 

 pumped into a number of small internal bal- 

 loons. The principal advantage claimed for 

 the non-rigid type by its greatest advocate, the 

 German Major Parse val, is that when not in- 

 flated it can be folded up and transported 

 from place to place. Before the War of the 

 Nations a French non-rigid, the Adjutant Vin- 

 cenot, held the record for the length of a single 

 voyage, having been thirty-five hours and 

 twenty minutes in the air. 



During the War of the Nations a number of 

 combination dirigibles and aeroplanes were 

 successfully flown. They were much smaller 

 than the true dirigibles, which are usually a 

 few hundred feet in length. A.C. 



Consult Berriman's Aviation; Curtiss and 

 Post's Curtiss's Aviation Book; Maxim's Arti- 

 ficial and Natural Flight. 



Related Subjects. The reader is referred to 

 the following articles in these volumes : 

 Balloon Langley, Samuel 



Curtiss, Glenn Pierpont 



Hammond Wright, Orville and 



Wilbur 



FLYING SQUIRREL, a small squirrel whose 

 name suggests power of flight similar to that of 

 the birds. However, it does not possess ability 

 to fly. It has a fold of skin along each side 

 of its body, connected with its legs, enabling 

 it to make long, flying leaps through the air, 

 its flight sometimes extending as far as sixty 

 feet, but always in a downward direction. It 

 is nocturnal in its habits, that is, it is abroad 

 at night, and it is easily tamed. It so closely 



resembles in color the decayed tree trunks in 

 which it makes its home that it is almost in- 

 visible. It feeds on nuts, leaf buds, birds' eggs 

 and sometimes on young birds. The smaller 

 species are common to North America and 

 Europe. The common flying squirrel found in 



FLYING SQUIRRELS 



the Eastern United States is six to seven inches 

 long, exclusive of the tail, has extremely soft 

 fur, which is of little commercial value, and 

 soft black eyes. The larger flying squirrel, or 

 taguan, is found in Indian and east Indian 

 regions, and is sometimes called the flying 

 marmot, or flying cat. See SQUIRREL. 



FOG, or MIST. When a cloud is formed 

 at so low a level that it rests on the ground 

 or on the surface of the sea, it is known as jog, 

 but when it presents only a faint cloudiness it 

 is called mist. Fogs often appear at sea when 

 the cold winds from icebergs blow across a 

 warm region where the atmosphere is filled 

 with moisture; the manner in which they form 

 under such conditions is explained in the arti- 

 cle HUMIDITY. A warm wind blowing into a 

 cold atmosphere will form fog, and many of 

 the fog banks and cloud banks so common off 



