688 



TORTo: 



other*, resulting at length in what appeared to be 

 their complete anorptkm." 



M are typical examples of general tornado de- 

 F-ripli'ms, all of winch indicate wind oppositioa 

 -:le winds set-ill always in prevail, probably 

 in different strata of the ttOMMpbflm, UM south wiinl 

 n-uallv. perhaps always, tin- lower. This warm ami 

 humid south wind naturally rises, while the cold north 

 wind as naturally descends. Thus two strong and 

 opposite air currents, which hud been moving in dif- 

 ferent layers of the atmosphere, meet face to face. 

 The result seems necessarily the same in air as in 

 Water, the formation of a vi.ironms eddy or vort. -x. 

 whose energy depends upon that of its coiisiitueiit 

 winds. In this ease the escape is upwards, and the 

 descent of the eddy to the ground is probably a conse- 

 nucii'-e of the effort of the winds to pass each other. 

 The opposing air currents have widely extended fronts, 

 niore or less angularly inclined to each other, so that 

 they Dome to-'clher gradually, like, to use a homely 

 illustration, the meeting of the blades of shears. To 

 this the progressive movement may tie duo. The vortex 

 is generate! at each iiieelin.il point of the 



wind*, and vanishes in the rear as it forms in front. 



ed of progression indicates that of meet-ibgof 

 the angul ir wind fronts, and depends on the width of 

 tlie aii-'le. while its irregularities are doubtless due to 

 the variations of speed and direction in the winds to 

 which it owes its origin. The final prevalence of the 

 north wind at the surface seems to indicate a reversal 

 of position in the two air currents, the north having 

 descended to a lower, the south ascended to an upper 

 stratum of the atmosphere, so that they once more 

 pass without opposition. 



ien. (ireeley's list of destructive tornadoes is given 

 in part in the following table, some of the less destruc- 

 tive being omitted : 



Low 



State. I '.<- Killed. Injured. Houses. Value. 



HIM. May 7, |S|M. :it7 10H ..._ $l,2t>U,000 



June M. 1-1.'. 500 



Conn. Aug. 9. 34 28 2,000,000 



Mo. April 18, 1880. 101 COO .. .. 1,000,0(10 



Iowa. Jun.-ir.l-si>. 100 300 260 1,000,000 

 Miss. April J.'.lss.i. 51 200 100 300,000 



Wi*. May 18, 1883. 18 100 17'..ipi 



Minn. An;. '.'I, I".!. 28 80 400 7(K>. 



Ark. N..V. L'|. 5 182 60 300,000 



IV!.. in, 1--I. IH I.''. 



Dk. July 28, 1884. 1". 18 



\Vi. Sept. 9,1-- 1. 6 '!> 30.5 4,000,000 



N. J. Aug. 3, 1885. 6 100 .000 



Ohio. Sept. s, 1885. 6 100 600, < 



Minn. A|.ril 14, 1886. 74 136 186,000 



Ohio. Mav 12, 1886. 57 



Kan. April 21, 1887. 20 237 330 1,000,000 



Many of these tornadoes extended through 

 States, that of April It. issii, for instance, travel ing 

 3V) miles from Council Hluffs to Sank llapids. Minn., 

 which town it destroyed. That of April IS. 

 utterly wrecked the town of Marshfield. Mo. Many 

 other towns and villages have been partly or wholly 

 destroyed, and it seem.- evident that, in the fuller set- 

 tlement of th- Mi--issippi Valley States, a greatly 

 in -rc.iM-d annual destruction may i 1 from 



this source. The fore-is of that section often | 

 great lanes of broken-down and torn up trees indica 

 tin? the tracks of tornadoes in the past. As towns 

 replace forest and cover the prairie lands, the danger 

 will proportionately inrrea-c. Tin- Atlantic - 

 while I' -s frequently visited hy this terrible a'.-eiit of 

 destruction, are by no mean- exempt. Several of (he 

 example* in tlio table given were in the K:i-t- thnt of 

 Aunuit 3, Is-C,, passing through the city of Camden. 

 N .1 . where it made frightful havoc. A more recent 



r of thin kind was thai of .January '.I. I 

 which a violent tornado struck the cily of Keadinir. 

 I'*., fortunately on]y on its outskirt, utterly wi 

 * silk-mill and a railroad paint-shop, with a loss of 24 



killed. 9$ injured. Tliis tornado passed over a con- 

 siderable extent of country, but, by good fortune, 

 struck no oilier town. What w.i- probably an I 

 paining tornado passed over Western 1'cnnsvlvania on 

 the same day. doing vreat damage in the oil-lields, 

 blowing down the -u-|.eiiMon bridge at Niayara, and 

 wre<-kiiig an unfinished building at 1'iltsburg, wiili con- 

 siderable loss of life. M.) 

 TOUTOISK. one of the names given to the T<*tu- 

 Jiiinlir. or shell-beat in:: reptiles, which 

 , 4-i :IV<1 known al-o by the common names 

 AB Ken)' of turtle and terrapin. Asattii' 



used the tendency is to restrict the title 

 of tortoise to the marine species, that of' turtle to the 

 land species, and tlialof terrapin to fresh wateran 



of the family J-Jiiii/ili'ilir. In the I'liitcd States 

 the name of terrapin is applied only to a^few - 

 <d' this family which are used for food. The I niied 



:ias in ,11 41' or 43 specu s of tortoises, of which 

 all, with the exception of the musk tortoises. ;n 

 to a greater or le.-s extent for food, or for oil* 

 noiiiical purposes. Yet only a few species are in actual 

 demand, including the marine L-IVCII turtle. 'J or 3 

 species of soft-shelled turtles, the snapping turtle, tho 

 gopher or land turtle, and i! or 4 species of terrapin. 

 Of the latter much the most highly prized is the 

 diamond back: salt -water terrapin! .Mn'm-nli ninnix /..(//..,- 

 trix). This species is found in the salt mai.-hes along 

 .ist from Massachusetts to Texas and also in 

 South America. The northern terrapin, however, are 



i v delicate in flesh than those of the (Jnlf, and the 



principal market supply comes from Chesapeake Bay 



and tin ast of the Carolinas. Egg Harbor, N. .)., 



also furnishes some very fim es. 



The diamond back terrapin is of small size, the 

 under shell of the female averaving (i or 7 ins. in 

 length, its extreme le.ngth being In ins. The weight 

 is 4 or 5 Ibs.. though in extreme cases 1(1 llis. is 

 reached. It has a Very large head, with strong and 

 cutting jaws, small eyes, and short and thick neck. 

 The shell is oval, moderately convex, and of : dusky 

 olive-green color, \vith darker concentric lines. Tho 

 .-termini, or lower shell, is yellow, with dusky concentric, 

 lines. This specie- is very shy and active, swims well, 

 and runs with considerable speed on land. The males 

 are smaller than the females, rnileh^ less valued, and 

 sell at a considerably lower price. The fishing I 

 Lists from Oct. 1 to June 1. October and Novcmlicr 

 iM-ing the best months At this period the terrapin 

 has buried itself deeply in the mud for its winter 

 hibernation, and is very fat and juicy, ll is easily 

 found by a mound of mud raised above its hiding- 

 place, and is taken in considerable (piantities. Th> 

 L'.') to KKI in number, are laid in early sprite 

 in egg arc the mo.-t highly valued, the CI/L'S be ing tho 

 tidbit of epicures. In their liest season terrapin sell 

 at from $15 to $3f> and even $50 per do/en, according 

 to size. The males arc used only in soups, and bring 

 about $3 per dozen. Many terrapins are caught in 

 summer, and penned in "yards' 1 till the mark- 

 son. They arc found to breed in captivity, and efforts 



have bcei ide. with some success, to raUc them from 



eggs laid under such circumstances. This is impor- 

 tant, as the annual catch, never large, is steadily de- 

 creasing. Philadelphia is the principal market for 

 terrapin. thoiiL'h lartre quantities arc supplied toother 

 seaboard cities, and many arc sent to the cities of the 

 interior. 



There are from 1"> to 20 species of fresh water 

 terrapins in the I'nited States. These, formerly 



101 /'//"/'. but now divided into - 



L-enera. differ from the, land-turtles in having their feet 

 more webbed and expanded, anil the shell of the back 

 more flattened. Three or four species of the genus 

 /V",/r;/n/.arc of m-irketable value. Of tie 

 liellicd terrapin. /' rnr;n*i. is usually 10 or 11 ins. 



It- upper shell is of a dusky brown color, with 

 blutchcs and lines of red ; the lower shell is of a dusky 



