102 REPORT — 1844. 



Powers of bars by the single series process,") „ - 7.4.7.4 q.q T^t„i 07.1 

 in figure of 00 combination /'' '' /4, 74j 8J. lota\ 67 1. 



Powers obtained by the double series pro- 1 g.^^ . g. g. ^q, 1 07. Total 48-2. 



These powers, it will be noted, are very unusual. The last bar of the series was 

 found to weigh 4050 grains. Its lifting power, therefore, was not less than eighteen 

 times its own weight — a degree of energy, in a magnet of such a weight, as I had 

 never before witnessed. The average power of the set of bars was 9'6 lbs., or nearly 

 seventeen times the average weight. The load sustained when the five bars were 

 put together as a compound magnet was of course much reduced proportionally. 

 Before the removal of the conductors, indeed, the small magnet supported a weight 

 of 44-5 lbs. ; after the breaking of the contact, it sustained a lead, rapidly but progres- 

 sively attached, of 37 lbs., or above nine times the weight of the instrument. 



The same process of magnetic manipulation, in which the magnetic energy is deve- 

 loped through the medium of an interposed bar or bars, is found to be exceedingly 

 effective in its application to cast iron bars of the horse-shoe form. Through the 

 kindness of my friend Henry W. Wickham, Esq. of the Lowmoor Iron Works at 

 Bradford, I obtained bars of cast iron of the best quality, and made very hard by being 

 cast on a cast iron plate, for a large compound magnet of the horse-shoe form of this 

 species of iron. The bars measured twelve inches from the curved extremity to the 

 poles, and weighed on an average about 5'8 lbs. Their capacities for magnetism, as 

 developed by the new process, proved to be very considerable. 



Magnetized in the single series form, by a very powerful horse-shoe magnet, is the 

 best mode hitherto described ; the lifting powers of four of these bars were, — 



First trial, before the separation of c i ^ ± 



,■•',, ^ •' Subsequent or permanent power, 



the conductor. 1 x r- 



14; 9-5j 7; 12. Mean 10-5 lbs. 12-5; 7; 7j 8. Mean 8-5 lb.'. 



Masnetized by the new, or double series process, the powers were, — 



23-5; 17-5j 18-5; 18. Mean 19-5 lbs. 150; 10 5; 10-5; 11. Mean 11-8 lbs. 



Straight bars of thin hard steel were next subjected to trial by the same process, and 

 its efficiency in developing the utmost power of the bars, by the agency of a horse-shoe 

 magnet, was again proved. In this case three hard steel plates were placed in a 

 straight line at the end of each other (according to a well-known arrangement), these 

 being magnetized by a single strike of a horse-shoe magnet from end to end, with a 

 similar series of hard plates interposed. Each of the three plates of the lower series 

 was found to be magnetized to saturation. A result, apparently similar, but not yet 

 strictly tested, was obtained by one stroke of the horse- shoe magnet over a single 

 hard cast steel plate, with a plate of iron interposed. Here the iron acted as a con- 

 ductor along the whole magnet, so as to render the formation of a parallelogram of 

 two steel bars with iron conductors across the ends unnecessary. 



Thus by means of this new process, the principle of which simply consists in the 

 developing of the magnetic energies of a magnetizable substance, not by the direct 

 action of a magnet, but through the medium of a magnetizable substance of like 

 dimensions interposed, the horse-shoe magnet, an instrument so compact and con- 

 venient for practice, becomes available for the magnetizing of almost all kinds of 

 bars or plates capable of being constructed into permanent magnets. 



On the Great Fountain at Chatsworth, erected by the Duke of Devonshire. 

 By Mr. Paxton. 



This fountain is supplied with water from a reservoir which covers eight acres. 

 The fall is 381 feet, and the height which the water attains from the fountain, (or 

 which it is expected to attain when brought into full operation,) is 280 feet*. 



On the Filtration of Water for tlie Supply of Towns. By B. G. Sloper. 

 The high-pressure plan, through sand, was recommended. 



* A report on this subject has been undertaken. 



