The Departmental Committee of the Board of Trade, sitting in 1909 to consider railway accounting forms, while recommending ton-miles to the careful consideration of those responsible for railway working in Great Britain, considered the question of their necessity in British practice to be still open, and held that, at all events, they should not be introduced under compulsion.
Elliptic orbits, and a parabolic orbit considered as the special case when the eccentricity of the ellipse is 1, are almost the only ones the astronomer has to consider, and our attention will therefore be confined to them in the present article.
Another question with which the textual critic of modern authors must be prepared to deal is the relative importance of different editions, each of which may have a prima facie claim to be considered authentic. Thus Shakespearean criticism must decide between the evidence of the first folio and the quartos: the critic of Shelley's poems must consider what weight is to be attached to the readings in the posthumous edition by Mrs Shelley, and in unpublished transcripts of various poems. Where there is great or complicated divergence between the editions, as in the case of Marlowe's Faustus, the production of a resultant text which may be relied upon to represent the ultimate intention of the author is well-nigh impossible.
In this case it is generally more convenient to consider as unit of heat the thermal capacity c of unit volume, or that quantity which would produce a rise of one degree of temperature in unit volume of the soil or substance considered.
If the latter are considered to be in an early state this presents no difficulty; but if both Antarian and carbon stars are held to be evolved from solar stars, we may consider them to be, not successive, but parallel stages of development, the chemical constitution of the star deciding whether it shall pass into the third or fourth type.