TO THE VICE-CHANCELLOR, CAMBRIDGE.
                                        (Draft of a Letter.)

                                                                       Glenlair, 5th July 1873.

     I enclose a provisional list of fixtures and apparatus required for the Laboratory.

     At present I am not able to estimate the prices of many of the articles.

Some of them are in the market, and have simply to be ordered; others require to be constructed specially for the    Laboratory.

     I have begun with a list arranged according to the places and rooms in the Laboratory, but, of course, all small    things must be kept in cases, either in the apparatus room, or in the special rooms.

     The special duty of the professor of experimental physics is to teach the sciences of heat and electricity, and also    to encourage physical research. The Laboratory must therefore contain apparatus for the illustration of heat and   electricity, and also for whatever physical research seems most important or most promising.

     The special researches connected with heat which I think most deserving of our efforts at the present time are   those relating to the elasticity of bodies, and in general those which throw light on their molecular constitution; and    the most important electrical research is the determination of the magnitude of certain electric quantities, and their   relations to each other.

     These are the principles on which I have been planning the arrangement of the Laboratory. But if in the course of    years the course of scientific research should be deflected, the plans of work must vary too, and the rooms must   be allotted differently.

I agree with you that the income of the Museums must be largely increased in order to meet the demands of this  and other new buildings, and I am glad that the University is able to increase it.

     It is impossible to procure many of the instruments, as [353] they are not kept in stock, and have to be made to    order. Some of the most important will require a considerable amount of supervision during their construction, for    their whole value depends on their fulfilling conditions which can as yet be determined only by trial, so that it may  be some time before everything is in working order.