AuciusT 31, 18^<;J.] 



SCIENCE. 



281 



special posilion, or referred to such special axes, as 

 reduce the general problem to a specially simple one. 

 The speaker then drew the proji-ctions of three 

 conjugate diatueters of a general ellipsoiil upon the 

 hoard, stating that this was the best method of de- 

 fining that body. He then proceeded to fiml the pro- 

 jections of the enveloping cylinders, and the shadow 

 of the body; which he showed coulil as easily be done 

 for the general ellipsoid, in a perfectly general po^i- 

 tion, as for special cases. In fact, it appeared that 

 problems on this body gained nothing in simplicity 

 by special meihods and devices which detract from 

 the generality of the treatment. 



List of other papers. 

 The following additional papers were read in this 



section, some of tliem by title only : Tidal observa- 

 tions on soundings distant from shore, by ./. M. 

 liiUcheliler. Investigation of light variations of 

 Sawyer's variable, by .S. C. ClmuJler. Standard time- 

 pointer and a lime longitude dial; Sy>tem of alge- 

 braic geometry, by .Samuel Kmemon. The calculus of 

 direction and position, by E. M'. Ihjde. Observations 

 on the transit of Venus made at Columbia college; 

 Description of the new observatory at Columbia 

 college, by J. K. Rees. The light variations of T. 

 .Monocerotis, by E. F. Saici/er. Method of observing 

 eclipses of .lupiler's satellites, by I). P. TodU. 

 Conic sections in ilescriptive geometry, by J. Ji. 

 W'ebh. Descriptive geometry applied to the general 

 cllipioid, by C. M. Wiiudionrd. Some observations 

 on Uranus, by C. A. Youwj. 



PROCEEDIXG.S OF SECTION B. — PIIY.SICS. 



P.VPERS READ BEFORE SECTION B. 



[C0ntinued.'\ 



The tornado at Racine, May 18, 1833. 



BY P. R. HOY OF lt.\CIXE, WIS. 



A CURIOUS mistake preceded the re.iding of this 

 paper. There was some confusion between the ab- 

 stracts of this and another paper on a tornado, which 

 wi're snl)mitted to the sectional committee; and the 

 other paper was entered on the daily programme, but 

 was withdrawn. 



Mr. Hoy's paper began by stating that the early 

 part of the d.iy was pleasant, but about 6.4.5 in the 

 evening two clouds of ominous appearance joined, 

 from opposite quarteis of the heavens, and at once 

 the cyclone began. Its general direction was to the 

 north of east. There was no rain at Racine with the 

 storm, but there was noticed a very strong odor of 

 ozone while the cyclone was at its height. At the 

 start it was barely two rods wide, but when it reached 

 Racine it had expanded to twenty rods. Its motion 

 was rotary and oscillatory, ami all debris was thrown 

 to the centre of the track. When the cyclone crossed 

 the lake it formed huge waterspouts, one central, and 

 seven to eight accessory, whirling about the main 

 trunk. 



Prof. H. A. Rowland proceeded to discuss the paper 

 as follows: Most observers of tornadoes just perceive 

 that there is a whirling motion of the air, and it 

 knocks down objects, and that is the principal thing 

 they see. But that is very ordinary observation. Of 

 course, a column of air in such swift rotation will 

 tear houses down, spurt water up, and do every thing 

 of that sort. The particular point which I observed 

 in this paper w:is the description of the formation of 

 the tornado. The phenomenon which is to be ex- 

 plained is the formation of the tornado, and very 

 few have observed this. This description was very 

 short; merely, that, over in the west or south-west, the 

 rloiids formed. Of course, to an observer from the 

 west, one would appear north, and the other south. 



The point I wish to bring out is, that there was 

 lightning passing between the two clouds. In Mr. 

 Finley's description of six hundred tornadoes, I do 

 not see any similar account. Many observers have 

 seen lightning play around these clouds, but not pass- 

 ing between the two clouds. Mr. Finley applied to me 

 to know whether there was any thing in the electrical 

 theory of a tornado. Of course, any theory of I he 

 destruction being caused by electricity, houses being 

 attracted, etc., — all that is mere nonsense. AVe know 

 that the attraction of electricity is only a mere frac- 

 tion of an ounce to the square inch. Before the 

 force becomes suffinent to raise a great weight, a 

 spark passes, and adischargeof electricity takes place. 

 But in this case (these two clouds p.assing from north 

 to south, and boiling up, having Hashes of lightning 

 playing round them), I thought there might be some- 

 thing in the electrical theory, as far as formation 

 W.1S concerned; and I calculated for the signal-service 

 and Mr. Finley what amount of energy there was in 

 two clouds approaching each other in this way. The 

 rotation of the earth will cause them to come together, 

 not in a straight line, but a little aside from each 

 other, forming a spiral motion. The direction of the 

 rotation of the tornado is a necessary consequence of 

 the earth's rotation: so that it might be possible to 

 have these electrified clouds api>ro,ich each other by 

 mutual attraction, and form a tornado at the ])oint 

 where they meet. I calculated the energy, and found 

 there was sufficient for a rather small tornado in the 

 case I took. I would not be willing to 8.ay that is 

 the theory of all toruiidoes. I say that it is only 

 possible. There is a great deal more energy in a mass 

 of air heated up to a considerable temperature, and 

 rising, by force of gravitation, — a great many times 

 more. If it were not for the electrical phenomena 

 ob.served in the case, I should say there was very little 

 probability of the electrical theory. I believe Mr. 

 Finley will direct the signal-service observers to 

 watch the direction of the wind, if it flows in from 

 all directions at the point where the tornado i> fcumed, 

 we should determine it to be due to the rise of hot air 

 at that point. When the ground is very hot and the 



