1 9 4 D O C S . 2 2 8 , 2 2 9 D E C E M B E R 1 9 1 9 228. From Robert W. Lawson 21 December 1919 [Not selected for translation.] 229. From Hendrik A. Lorentz Haarlem, 21 December 1919 Dear Colleague, During your last visit we again vividly felt the high value of an exchange of ideas with you, along with the inspiration coming from you for the physicists and stu- dents in Holland.[1] The desire has therefore arisen to have you appear here from time to time with some regularity. The faculty (which is presently chaired by Kuenen)[2] was in immediate unanimity in this wish, and it found enthusiastic favor with the directorate of the “University Council,” a governing body whose task is to promote in various ways, independently of the government, the interests of the Uni- versity of Leyden.[3] It has the authority to name “bijzondere hoogleeraren,” let us say, “Extraordinary Professors,” and would now like to create for you such a pro- fessorship “of physics” (without any closer designation, so that you are left com- pletely free) for a period of three years, and more precisely, with an annual salary of two thousand guilders.[4] The directorate has commissioned me now to approach you with this request if, as is very much hoped, you declare your receptivity to an appointment, then the relevant proposal will be made at a meeting of the university council to take place on 8 February. I must ask you to consider this 〈matter〉 letter as confidential until then. Allow me to add that it is by no means expected that you give away a large por- tion of your time and labor. It will be very satisfactory if you came to Leyden once or twice a year for a few weeks and we would leave entirely up to you how you would like to arrange your activities. This applies specifically also to the question of the extent to which you would like to deliver “lectures” or “talks.”[5] Only for the first time, an inaugural lecture would be, if not absolutely necessary, nonethe- less preferred. We would of course procure the necessary thalers for it. I must emphasize, in particular, that there is not the least thought that you loosen your commitments to Berlin in any way. Our Berlin colleagues will undoubtedly understand that we would like to have you here from time to time and that, for inst., Kamerlingh Onnes would put great store in discussing problems being addressed at his Cryogenic Laboratory with you.[6] I need to say nothing about Ehrenfest he has of course already written you.[7] As far as I am concerned, you would please