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An Account of fome Magnctical Experiments made 
before the Royal Society, on Thurfday the lift of 
April 1737. by "Dr. Defaguliers. 
I T is well known, and has been often found by 
Experience, that an iron Bar untouch'd by aLoad- 
ftone, will, with its upper End, attrad the North 
End of the Needle of a Compafs, when the faid Bar 
is held upright, and the South End of the Needle with 
its lower End, when applied to it, ftill in a perpeng 
dicular Pofition, whatfoever End of the Bar be held 
up ; unlefs the Bar has acquir'd a fix'd Pole by having 
been long in a vertical Pofition. But if the Bar from 
a vertical be brought to an horizontal Pofition, the 
Needle will return into the Situation it had before, 
which was in the Magnetical Meridian, the Bar being 
then at Right Angles to it. Upon railing or finking 
the End of the Bar which is fartheft from the Needle, 
the one or the other *End of the Needle will bedn to 
O 
move towards the Bar. Such a Bar has in itfelf no 
fix'd Magnetic Virtue 5 but if it had, it mud be heated 
red-hot, and then cool'd in an horizontal Pofition. 
A Bar thus prepar'd is fit to make the following Ex- 
periments, communicated to me by Monfieur c Du 
Fay . 
Hold the Bar upright, and give it a Blow or two 
againft the Ground with its lower End 5 and that End 
will attrad the South End of the Needle, when the 
Bar is held horizontal, and at Right Angles to the 
Magnetic Meridian : The other End held horizontal 
in the fame manner, will attrad the North End of the 
Needle. Invert the Bar, and the Virtue of it will 
be 
