The subject of tropical mortality has in the past received a moderate share of attention, and actuaries have at their command various mortality experiences for climates other than temperate. These without exception show higher, in some cases much higher, mortality than that to be expected in this country. These notes have been made with the object of giving some short account of various tropical diseases to which this higher mortality is no doubt to be attributed.

The very marked improvement during recent years in tropical vitality among assured lives can be dated from the closing years of last century, when the true cause of such diseases as malaria, filaria, and yellow fever was discovered to be their propagation by certain mosquitoes. Correct methods of prevention or at any rate mitigation of the spread of these diseases were then able to be taken.

Although mosquito-borne fevers account for most of the increased mortality in the tropics, certain diseases of the intestinal tract, such as cholera, dysentery and sprue, have their part in bringing about this undesirable state of affairs.

Other diseases which cannot be held to have much effect on assured lives, however disastrous they may prove to the native populations, are leprosy, hook-worm disease, beriberi, and pellagra ; and of these some shorter notes are given.

In his inaugural address the President, dealing with the subject of research in connection with climatic and occupational rates of mortality, suggested that the Faculty might consider the advisability of the question being remitted to a committee to consider and report. In consequence a Sub-Committee was appointed by the Faculty Mortality Committee on 21st November 1930 to consider the subject of extra premiums for occupational and climatic risks generally. The time therefore seems appropriate for the submission to the Faculty for discussion of a paper on this subject.

The paper falls naturally into two sections. Section I contains a summary of the work which has been done in the past, chiefly in this country and America : it is hoped that it will form a convenient source of information on the subject, and further, that it will be of use inasmuch as any new method should rest on the basis of a full study of what has been done in the past. It may be mentioned that no attempt has been made to criticise or in any way to indicate the value or otherwise of the studies summarised. Endeavour has been made to include all the more recent studies which have a bearing on the subject under discussion, but it is of course difficult to avoid overlooking some which should have been included.

In Section II consideration is given to the methods used in the past, particularly to those employed in connection with the Joint Occupation Study. This leads to the formulation of an object for the proposed statistical investigation, and attention is then given to the problems of attaining this object with particular reference to the needs and practice of assurance companies in this country. A brief description is given of how the proposed investigation might be undertaken, and the following subjects are dealt with :—

• (a) the hazardous groups to be investigated;

• (b) the methods of recording the data ;

• (c) the methods of collecting the data.

The relation of the proposed investigation to the Continuous Mortality Investigation now proceeding and to any medico-actuarial investigation which, may be contemplated is discussed ; the suggestion is made that a comprehensive system of collecting the data should be instituted and that the information necessary for a standard, an occupational and climatic, and a medico-actuarial mortality investigation should be embodied on one uniform mortality card.

The paper commences with a résumé, with statistics, of the development and extent of aviation in its various branches up to the present time. It goes on to analyse the risk incurred in each, and to discuss principles of assessment of the risk and methods of calculating extra premiums. The duties involved in the various classes of employment connected with aviation are considered, and statistics submitted dealing with accidents and casualties attending commercial aviation in Britain and in the United States. Government supervision and the regulations in force regarding the issuing of certificates of airworthiness and licences to pilots, navigators, and ground engineers are outlined. Royal Air Force flying in its different branches is dealt with and statistics of casualties are given. The answers given to a questionnaire addressed to 60 offices transacting business in Great Britain together with the extras charged for different types of risk are analysed. The question of ordinary life assurance offices reassuring aviation risks with a company specialising in such insurance is discussed. The lack of statistics is commented upon, and stress is laid on the desirability of obtaining as soon as possible reliable statistical bases for the calculation of premiums to meet the demand for cover against aviation risks, a demand which in the nature of things will increase rapidly and must be met. In an Appendix are given the recommendations of the Actuaries' Club of Toronto and a supplementary proposal form in use by a Canadian office for cases where an aviation risk is involved.