The Path to Type-II Superconductivity
Round 1
Reviewer 1 Report
Comments
This is a very nice article describing the route from the first discovery of superconductivity to Type II superconductors, with some extra material thrown in. It is comprehensive and comprehensible with all the necessary facts, but without unnecessary detail. The English is excellent and very readable.
In the comments below I have listed a number of minor changes which the author might consider in order to make the text more consistent with the usual style of English. The only ones I do not regard as trivial are at lines 96 and 112.
Detailed Comments.
l. 23. 'law of corresponding states', no 'the'.
l. 74. 'electrical' for 'electric'
l. 88. There was a surprisingly long gap between the discovery of superconductivity and the Meissner effect. I seem to remember reading somewhere that this was because Helium was expensive and so hollow spheres, which did not show the Meissner effect, were used. I also believe there were earlier experiments on trapped fields which were a very sensitive test of the resistivity. A little information on this gap might be interesting if the author knows more.
l. 96. In my opinion cgs units should have been banned from journals many years ago. However what is certainly true is that units in a single paper should be consistent. Equation 1 should be put in SI units, as should the energy density. In fact I think this bit could be improved. 2.49x1014 eV/cm3 may be a small value, but it doesn't look like it. I suggest the energy density be given in meV per atom, or per electron, and compared with kTc.
l. 100 +6. ' dissipative' for 'dissipated'
l. 100 near l.101. It might be useful to point out that although superconductors show magnetism, these are due to currents in free space so that B=moH.
l. 105. A.B.Pippard was always known as Brian, never Alfred, which was the name of his father (also a distinguished scientist and FRS).
l. 109. Landau's first name is more usually written as 'Lev'.
l. 112. G-L expressed their energy as the Haelmholtz free energy/vol 'f' rather than the Gibbs energy 'G'. The lower case for the energy per unit volume is not too important, but the distinction between f and g, (or F and G), is. F is appropriate for systems at uniform temperature but G contains an external work term, usually B.H, but in superconductors H is rarely the external field. For a wire carrying a current it would be V.I, to say nothing of samples with a demagnetising factor. Use of G restricts the theory to a much smaller number of cases and is confusing.
l. 124. Units of flux are usually written Wb.
l. 142. The use of 'one' in this context is a little unusual, and has become rather associated with the Royal Family, who have now stopped using it after a number of satirical sketches. I suggest :
Nearly simultaneously anomalies in the specific heats and the magnetic properties of superconducting alloys had been observed in Oxford [11 ], Leiden [12 ], and Kharkov [13 ].
l. 159 'superconductor' for 'superconductors'
1. 69 'Sceptical' is more commonly used than 'skeptical', which is a little old fashioned
Comments for author File: 
Comments.pdf
Author Response
Thanks for the excellent review.
I have incorporated all suggestions, except for equation 10, which I presented in the usual way
Reviewer 2 Report
This is a historical review, not a research paper. It is very well written, but there are a couple of people who could have been mentioned. See attached report
Comments for author File: Comments.pdf
Author Response
Thanks for the excellent review.
I have incorporated all suggestions except for equation 10, which I presented in the usual way.
