200 INVENTIONS AND DISCOVERIES. 



ignition by the spark ; which we have, since then, seen him repeatedly 

 perform. Does Dr. Ritchie call Mr. Saxton's magnet one of the 

 temporary ? 



We subjoin a description of the magnet constructed by Mr. Saxton. 

 It is called a horse-shoe magnet, (very elongated,) and is formed of eight 

 shear steel plates, twenty-eight inches in length from the poles to the 

 centre edge, three inches wide, and forming together a thickness of 

 two inches and a half; at the greatest width of the curvature it mea- 

 sures nine inches, and at the poles seven inches across ; the poles have 

 a return inwards, towards each other, and are there separated by a 

 space of one inch and a half. The keeper, or lifter, which is made of 

 the purest soft iron, is four inches long, one inch and a quarter wide, 

 and one inch thick. Around the middle of the keeper, and occupying, 

 with its lower section, the space between the poles, is a wooden winder, 

 having about one hundred yards of common bonnet-wire, threaded, 

 from which the two ends, composed of four lengths of the wire twisted 

 together, are carried out, with a verticule curve of about three-fourths 

 of a circle, one of these twisted ends passing beyond each end of the 

 keeper, and resting upon the respective poles of the magnet. A small 

 wooden lever is so fixed to the winder and keeper, as to admit of the 

 whole being suddenly forced up from the magnet by a smart stroke ; 

 and a very beautiful and brilliant spark is invariably elicited, at which- 

 ever end of the wire is first separated from the magnet. 



It is Mr. Saxton's intention to add several plates to his magnet, and 

 to ascertain, by a series of experiments, the best size for the keeper 

 the best description of wire to be used the easiest mode of causing an 

 instantaneous separation of the wire from the magnet, and other inte- 

 resting consequences, the result of which we shall take occasion to com- 

 municate to our readers. 



Perkins' newly invented process for generating steam, is accomplished 

 by so placing a lining within the boiler, that a thin sheet of the fluid 

 which it contains, may be carried constantly over those portions of the 

 side of the vessel which are in immediate contact with the heat from the 

 fire, formed upon the discovery of the circulation of the fluid, under the 

 operation of heat, from that part of the boiler subjected to the imme- 

 diate action of the fire upwards. 



It is found that, as the heat is increased, the ascending current 

 becomes more rapid, that the agitation is more violent, and a relatively 

 augmented proportion of steam is produced ; whilst the metal, of which 

 the boiler is composed, is preserved from that destruction to which it is 

 subjected in the common process, wherever the fire happens to act upon 

 it with more than ordinary violence. 



A receiver is also placed in the centre of the boiler, into which, by 

 the circulation of the heated fluid from the bottom and sides of the 

 boiler, all dirt or other sediment is thrown ; by which another cause of 

 the destruction of the boiler is removed. 



In this article we omit the mention of other inventions and discoveries, 

 because we will not weary the reader. Our present object is to excite 

 attention to these interesting and useful speculations of creative genius 

 and scientific research ; our future aim shall be to continue to fix that 

 attention, and we hope to a good end. 



