28 



FARMERS REGISTER. 



[No. 1 



From Proceedings of British Association . 



RESISTANCE TO MOTION IN CANALS, IN KE- 

 LATION TO VELOCITY. 



Mr. Russell, of Eilinburgh, was called upon to 

 lay before the section the result of ceriain experi- 

 ments made by him on the traction of boats in ca- 

 nals at different velocities. On the general princi- 

 ple of the resistance of fluids to bodies moving in 

 them, was grounded the conclusion that it would 

 be an impracticable thing to move the cumbrous 

 boats upon canals at any but very low velocities, 

 except by an expenditure ol" j)ovver so great that 

 the ordinary methods of conveyance by roads 

 would be cheaper. It was believed, that the re- 

 sistance would increase with the velocity, by a 

 law so rapid in its variation, that lor two miles an 

 hour speed, there would be ibur times the resis- 

 tance of one rrjile ; I'or three miles, nine times that 

 of one mile ; for four, sixteen times ; and so on, 

 as the squares of the velocities. Here, there was 

 an obstacle to rapid communication by canals, 

 which appeared insuperable. Mr. Russell has 

 shown that there is practically a circumstance 

 which so completely modifies the application of 

 this principle, that when over a ceriain point of 

 speed is attained, the resistance, instead of in- 

 creasing when the speed is yet I'urlher increased, 

 in point of iact diminishes. In one of his experi- 

 ments, he found, for instance, that the resistance 

 to the traction of a canal boat, estimated by a dy- 

 namometer, increased with the velocity of its mo- 

 lion nearly according to the law of the squares, up 

 to 7^ miles per hour, being then 330 lbs. ; the 

 speed being then increased to 8^ miles per hour, 

 instead of further increasing, the resistance fell to 

 210 lbs. The speed was yet further increased, 

 and it increased again the resistance to 236 lbs. ; 

 yet, less, be it observed, than at 7^ miles ; 12 miles 

 an hour brought it to 352 lbs., scarcely more than 

 the resistance of 7^ miles speed. These results. 

 confirmed by a number of others, had maniii^^stlv 

 a practical application, and they have been applied 

 to the working of fast canal boats in Scotland. 

 Mr. Russell has devoted himself to the explana- 

 tion of them. He states, that where the water of 

 a canal is disturbed by any cause, as tor instance, 

 the admission of a rush of water momentarily into 

 one extremity of it, or the impeding of a body 

 moving in it, there is generated a certain wave, 

 whose motion along the canal is altogether inde- 

 pendent of the nature or velocity of the impulse 

 given to it, and dependent only upon the depth of 

 the canal; its velocity being precisely that which 

 a stone would acquire in falling down one-half the 

 depth of the canal. With this velocity, the wave 

 moves uniformly and steadily to the very end of 

 this motion, moving slower (if the depth of the 

 eanal remain unchanged,) bnt only diminishes its 

 dimensions, until it disappears, and this not lor a 

 very considerable space. He stated, that he had 

 himself followed waves a mile and a half; and 

 that they had been traced unbroken for three 

 miles from the spot where they originated. 



The velocity of the wave depending on the 

 depth of the canal, it is manifi^st, that each canal, 

 differing in depth fiom another, will have a differ- 

 ent velocity of wave, and that each part of the ca- 

 nal diffiering from another, will alter the velocity ol 

 its wave, and thus the waves near the shore will 

 move slower than near the centre of the canal, if 



the side be shallower than the middle. How, 

 then, have these IJicts their application to the phe- 

 nomena observed ? Thus, in the experiment de- 

 scribed above, the velocity of the wave ascertain- 

 ed by numerous experiments, was eight miles an 

 hour. As long then, as the boat moved at three, 

 four, five, six, or seven miles an hour, it remained 

 in the rear of the wave; the wave had no effect 

 on it, as the law of the velocities was the theoreti- 

 cal law. At eight miles an hour the boat was, in 

 point of fact, on the wave, and it might, indeed, 

 be seen about the centre of the boat lifting it out 

 of the water and diminishing the traction upon it. 



NOVEL EXPERIMENTS IN RAILWAYS. 



Since the opening of the Durham and Sunder- 

 land Railway, a novel experiment has been fried 

 upon the line, which proves the practicability of 

 rail road vehicles being propelled by wind. A 

 temporary mast and sail were erected on a vehi- 

 cle, which was set going at an easy rale. On the 

 sail being trimmed to the wind, the speed increased 

 to the rate of ten miles an hour. A train of five 

 coal wagons was afterwards attached, but no ad- 

 ditional sail hoisted. The train was set going as 

 easy as possible to give it motion, when the speed 

 increased to the rate above mentioned. The ex- 

 periment was repealed ll^r several days between 

 Sunderland and Hendbn, each way, with the 

 same success, and was witnessed by numbers of 

 spectators, who were much delLuhted with the no- 

 velty of the scene. —[£';)§•.] Mining Jour. 



EXTRACTS FROM THE PROCEEDINGS OF THE 

 AGRICl'LTI RAL C0NVK\T10N OF N. Y'OKK, 

 HELD IN ALEANV, FEliRUARY 2, 1837. 



[In a late No. of tlie Farmers' Register, we were 

 enabled, by the kindness of Dr. J. P. Beekman, a dis- 

 tinguished member of the Agricultural Convention, to 

 offer to our readers an interesting sketch, from bis own 

 pen, of the proceedings of that body, in advance of 

 the formal report and publication, which has since 

 reached us in the Albany Argus, and of which the fol- 

 lowing extracts form parts. 



It is proper here to correct a mistake which we fell 

 into, in our remarks in the communication of Dr. 

 Beekman. "The woik of Mr. Taylor, on agricul- 

 ture," which he mentioned, was not the "Arator" of 

 John Taylor of Virginia, as we then understood.] 



j^id of Government to ^'Agricultural Improvement. 



Mr. Buel, from the committee appointed to 

 report resolutions lor the consideration of the Con- 

 vention, reported in part, the following: 



Resolved, That in the opinion ofthis Convention, 

 agriculture is the great business of the state; that 

 upon its resources and improvements, the mer- 

 chant, mechanic, manufacturer, and all other 

 members of society, must depend mainly, for sub- 

 sistence and lor wealth; and that upon the intel- 

 ligence and virtue of those who manage its labors 

 — comprising, as they do, the mass of our popu- 

 lation — must materially depend our moral and 

 intellectual character as a people; — 



