There is, one might think, an element of risk in the performance of the most simple of operations in an industrial establishment; sometimes the risk is both grave and apparent whilst in others it may be said to be trivial and remote. Between these two extremes the degree of risk may vary infinitely. But if the risk is real and not merely fanciful reasonable care must be taken by the employer to avoid it and this duty may be performed either by devising a method of operation which does not involve such a risk or by the provision of appropriate safeguards. The general principles which define the responsibility of an employer in such cases are well settled and it is unnecessary to re-state them. But it is of some importance to notice that they operate to impose liability upon an employer whether the risk is consequent, solely, upon the physical operations which the performance of any particular task requires or whether, in the ultimate analysis, it is possible to see that the risk really results from the fact that the performance of those operations have been committed to a fallible human agent. This does not mean, of course, that where an injury has been caused to an employee by his own negligence he may seek to hold his employer liable but, rather, that the duty of the latter is not fully discharged unless, in the provision of safeguards, he has taken into account, not only that particular tasks necessarily involve particular risks, but also that inadvertence and inattention, short of positive negligence, are common concomitants of everyday work. The latter factors may be of considerable cogency in cases where the work of an employee exposes him constantly to the risk of injury unless there is unremitting care on his part but, in the nature of things, it cannot be of importance in the case of casual or isolated tasks of a simple character and which do not involve any real risk if ordinary care is used. Indeed, after referring to the observation of Lawrence J. "that it is not for every risky thing which a workman in a factory may do in his familiarity with the machinery that a plaintiff ought to be held guilty of contributory negligence" (Flower v. Ebbw Vale Steel, Iron & Coal Co. Ltd. [1] ), Lord Tucker in Staveley Iron & Chemical Co. Ltd. v. Jones [1] expressed considerable doubt whether that and other dicta to the same effect, "were ever intended or could properly be applied to a simple case of common law negligence where there was no evidence of work-people performing repetitive work under strain or for long hours at dangerous machines" [2] . The doubt, it may be observed, was shared by all of their Lordships who took part in the case with the exception of Lord Reid who did not discuss the point. Their Lordships did not, however, attempt to formulate any rigid rule which would exclude the necessity for contemplating the possibility of thoughtlessness or inadvertence - or to use what is, perhaps, a stronger word, carelessness - in circumstances other than those specified and as at present advised, I am content to conclude that, in considering whether a particular set of circumstances is sufficient to fasten liability on an employer, the relevant test involves a simple inquiry concerning just what precautions or safeguards the exercise of reasonable care requires and that, in making such an inquiry, the consequence of inadvertence or thoughtlessness is a variable factor which should be taken into account.