<div class="description">
<p>This paper describes a method for investigating the degree of magnetic uniformity along the length of straight bars such as are used for magnetic standards, and gives the results of tests made on a number of such bars. The bar to be tested is clamped between the poles of a suitably designed electromagnet and two small exactly similar coils slide along the bar at a fixed distance apart. These coils may be connected in opposition, and when the circuit is completed through a ballistic galvanometer the throw on reversal of the magnetising current is proportional to the difference of induction at the two parts of the bar occupied by
</p>
<br>Subjects: magnetism; measurements and use of instruments; Magnetic properties and materials A4100 Electricity and magnetism; fields and charged particles</div>
Internet Archive identifier