362 Miscellanies. 
5. The cooling of non-magnetic iron develops magnetism, or rather 
makes it more easy to be magnetised. 
Among the experiments from which these inferences were drawn, 
were the following. A needle, properly suspended, made sixty six 
oscillations in 60’, by the force of terrestrial magnetism. A mag- 
netised bar, of the temperature of 77° F., being placed at a certain — 
distance from the needle, with one end directed towards it, occa- 
sioned the needle to make one hundred and two oscillations in 60”. 
When the bar was cooled down to the freezing point, or 32° F., the 
needle made, in the same time, one hundred and four oscillations, 
and when the bar was cooled to 9.5° F., the oscillations were one 
hundred and five. On the other hand, when the bar was heated to 
112° F-., the oscillations were reduced to one hundred in 60”; when 
heated to 167° I’. they were ninety eight, and at the boiling temper- 
ature, 212° F., they were ninety six. 
The fifth result was thus obtained. *A piece of wire of soft iron 
being placed, at length, before a needle, the latter continued to make 
the same number of oscillations. The wire was then put into a large 
glass tube, and the temperature of it, by means of snow and ice, was 
reduced to 9.5° F. ‘The needle, which before had made sixty eight 
oscillations in 60”, being placed opposite a certain point of the cold 
wire, made seventy four oscillations in 60”, and placed opposite an- 
— other point, equally distant from the other end, it made likewise sev- 
enty four oscillations. But, when placed opposite the middle of the 
wire, no change was observed in the number. The temperature, in 
the course of eight hours, having been restored to its former degree, 
the needle made the same number of oscillations before every poimt 
of the wire. It is, therefore, (says the author,) natural to conclude 
that a’soft iron wire, cooled to 9.5° F., acquires the property of a 
rod feebly magnetised, and loses it on tsunHine its original tempera-~ 
ture.— Bib. Univ. Aout, 1831. 
18. New experiment in Mechanics.—F. Elice, professor at Genoa, 
has made known the following experiment. Suspend by a thread F, 
strong enough to support three kilogrammes, a weight B of 2.9 kilo- 
grammes, furnished with two hooks, diametrically opposite. Fasten 
to the lower hook another thread F’, capable of supporting one kilo- 
gramme. If the latter thread be gradually pulled perpendicularly 
downward, the upper string will always break, and never the lower 
string ; but the reverse will take place if the lower thread F” be pull- 
