But there is a vast difference between official and civil conditions. So far as the former is concerned it was a comparatively simple matter to introduce an efficient organization to cope with the problem, while the waste oil was recovered in bulk, the hospitals for treating the engines of the aeroplanes and motor vehicles being centralized. It is the degree to which facilities for satisfying the civil demand are scattered which renders collection and handling of the waste along inexpensive lines so perplexing. It might be satisfactorily overcome if each garage and private owner undertook to maintain a waste-bin and to commit all oil-soddened rags thereto for periodical collection by a centralized authority, either municipal or private. The waste would be obtainable at a low figure, possibly free, inasmuch as the majority of garage owners would only be too glad to be rid of it. Possibly it would be found profitable to strike a bargain along the lines of free waste in return for the de-oiled rags, particularly if they were dusters or cloths. In this event the waste oil exploiter would only be called upon to incur the expense of collection and the treatment of the spoil. The return of the cloths would not entail further expense, because they could be returned in exchange for another consignment of waste. The vehicle would have to make the journey in any event, and it might just as well make the outward trip laden as empty. It is quite possible, moreover, that the garage would be readily disposed to pay a slight charge for the cleaning of this material, particularly of cloths, so long as the sum was attractively below the price ruling for new supplies of the article. To the waste exploiter the value of the oil recovered should be adequate to defray all expenses of collection and treatment, and then leave a handsome profit capable of accretion from the disposal of the cleaned rags, which the garage did not require, for paper-making. It is merely a question of enterprise and organization, and in a large centre could be rendered a highly attractive and profitable venture. This fact is borne out by the experience of private firms. Of course, it is essential that the volume of spoil handled should be of sufficient bulk to keep the plant installed for the reclamation of the oil going to its full capacity, or to one approaching the maximum. This is possible in the case of a large private company, such as a railway, electric-generating station, or even industrial plant.