Electric motors for barrel cranes are not essentially different from those used for other purposes, but in proportioning the sizes the intermittent output has to be taken into consideration.
In steam cranes much the same principle obtains in proportioning the boiler; e.g.
In the present day engineers are in accord as to the principles of estimating the magnitude of the stresses on the members of a structure, but not so in proportioning the members to resist those stresses.
In proportioning the quantities of matrix to aggregate the ideal to be aimed at is to get a concrete in which the voids or air-spaces shall be as small as possible; and as the lime or cement is usually by far the most expensive item, it is desir able to use as little of it as is consistent with strength.
With regard to the proportioning of effort between the two theatres of war, contemporary military opinion, impressed by a sort of primacy which Bulgaria assumed in the league, by the more regular character of her army and her civil administration, and by the nearness of Constantinople to her eastern frontier, argued a priori that Thrace was not only the" principal "theatre, but the single important theatre in which practically all military effort should have been concentrated by both sides - a judgment which ignored the relation of strategy to war policy, and one for which in the sequel Bulgaria was destined to pay heavil y.