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XXXIV. On fome new Methods of fufpending Magnetic al 
Needles. By John Ingen Houfz, Body Phyfician to their 
Imperial Majejlies , , and F. R. S. 
HE very great utility which navigation derives from; 
the ufe of compafies, has been the principal reafon*. 
that fo much labour has been bellowed by many inge- 
nious men in fearching the belt method of fufpending 
magnetical needles, and that fome Academies of Sciences' 
have propofed confiderable premiums to be given to him; 
who fhould fucceed the beft in this important objedt. 
It has been, and is ftill, a general complaint, that fuch 
needles as were by their fize and figure fufceptible of 
the greateft magnetical power, and which were executed 
with the greateft exactnefs, and perfedtly balanced, were, 
for this very reafon of their fuperior accuracy, fo eafily 
put in motion, that the flighted: fhaking of the floor, oc- 
cafioned by the obfervers walking in the room, commu- 
nicates to them fuch a great quivering motion as to drag 
them out of their direction, and to render a confiderable, 
Read June 17 , 1779- 
time 
