William Scoresby to John Barlow¹   13 May 1843

Bradford, Yorkshire, May 13th 1843.

Dear Sir,

When lecturing at the Royal Institution², I was shown a large compound magnet made, I believe, in France? It is of the horse shoe form & constructed with receding bars so as to have the middle bars more prominent.

Would you oblige me by informing me of these particulars concerning it:-

1st. The weight of the magnet, exclusive of the conductor? [16lb]

2d. What weight it will now actually sustain? [28lb nearly]

3d. What weight (if known) it ever did sustain by actual trial? [not known]

4th. The maker of the Instrument if known? [Germany Dr. Schmidt]

5. The number of bars? [seven]

6. The dimensions of the whole - viz.

<1> Length from a to a [9 1/2]

<2> Breadth - b to b [4]

<3> Breadth of each bar, b-c [1 1/4]

<4> Total thickness of the magnet, d-d (fig. 1) [2 1/2]

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I am anxious to know the size & power of this Inst. having constructed one of a similar form from what I am wishful to compare with it, so as to know the advantage I have gained. Mr. Anderson I am sure would kindly undertake the trial & measurements. [Magnet badly used & now at low ebb probably]

If the instrument is put together with screws, I should be willing to remagnetise it & prove its intenest [sic] powers if I could get it sent here. But the answering of my enquiries would be sufficient for my object. I feel assured you will kindly excuse this trouble. [is put together with screws]

Having taken a copy of my questions, a mere reference to numbers will do[.]

I remain Dear Sir | Yours very faithfully | W. Scoresby

The Secretary of the Royal Instn

P.S. I beg to be kindly remembered to Dr Faraday, whose health, I hope, is favourable.