TRANSACTION'S OF tiECTIO>' G. 807 



the crank-pin, which is eflected by means of a centrifugal oiler attached to the 

 crank disc. It may be seen from the foregoing that, when once steam is up, the 

 fires, the water supply, the oiling, and the speed of the engine require no further 

 attention. But, when first starting, a sufiicient pressure is required in the boiler to 

 work the atomisers, and for this a hand air-pump is provided. A few strokes of 

 this pump will suffice to start the fires, and it is only necessary to pump slowly 

 for five minutes to raise sufficient pressure of steam to keep them going, fifteen 

 minutes in all being required to get steam up to 100 lbs. per square inch. 



As regards the other requirements of small motor.'*, the Shipman engine is 

 compact, not heavy, and simple to understand, so that it neither requires much 

 space, strong foundations, nor a skilled attendant. An engine developing 4i h.p. 

 on the break uses 4'21 lbs. of petroleum per h.p. ; and this, at Id. per gallon, would 

 give the cost of running at imder 'M. per break h.p. per hour. 



4. On the Disengaging of Boats, 8fc. By E. J. Hill. 



At the meeting of the Association in 1872 the author described a new hook for 

 lowering and disengaging parcels, boats, and other objects, which shortly after- 

 wards was very generally adopted, over 10,000 sets being at present in use. 



After having considerable experience of this appliance the author in 1879 

 designed a simpler form, which may be described as a hook, shaped in the form of 

 a horse's head, working in a link or shackle, and this in it.s turn has resulted in the 

 form exhibited. One of the principles in view in all three systems is that the hook 

 shall consist of a solid piece of metal, and not be altogether dependent upon the 

 proper working of the parts added to it. 



The new hook is a solid piece in the form of the letter G. Through the thick 

 or back part of this G is a slot to admit of a small traverser having a U-shaped 

 recess at one end which passes into the opening of the G, not only filling up the 

 apertui'e but forming a perfect O. The upper part or actual hook of the G is 

 curved round to such an extent that a ring or hook when engaged is safe to an 

 angle of about 45°, and therefore it is impossible with a fair strain for the traverser 

 to be moved ; but, when this strain is taken off", the ring is inclined to fall into 

 the U of the traverser, and of course is easily withdrawn. When it is required to 

 prevent the traverser being moved in the end which projects through the back of 

 the G a slot is made, in which a small flat locking key works. A pin or check is 

 fijiced on the traverser to control it in its movements. One of these hooks is fixed at 

 each end of the boat pointing in the same direction, namely, towards the bow. 

 By attaching a piece of wire rope to the two traversers the hooks are made to 

 work simultaneously, as was demonstrated by means of models. This plan can be 

 worked safely in several ways, either by the men in the boat, the coxswain of the 

 same, the officer in charge of the lowering on board the ship, or automatically, in 

 all of which cases the reliability of the working of the hooks is ensured. 



The author concludes with a reference to the increased interest now being taken 

 in all matters connected with the saving of life at sea. 



5. The old Orkney ClicJc Mill. By Professor A. Jamieson, M.Inst.C.E. 



The author, during a recent visit to the Orkneys, while inspecting one of the 

 mountain burns that run down to Birsay Loch, came across a specimen of the old 

 Click Mill, said to derive its name from the chck-clack noise created by it when at 

 work, which is supposed to have been introduced into these islands several cen- 

 turies ago by the Norwegians. The interesting points about it are : — (1) It is the 

 only remaining mill of its kind in Orkney ; and (2) it is very like the latest and 

 most perfect form of horizontal turbine in general conception and arrangement, 

 for the water comes down near the centre on one side and flows freely away to 

 the tail race. The farmer, Mr. Nicol Folster, stated that the mill had worked in 

 its present position over 100 years. The construction and action of the mill were 

 explained by means of a sketch and explanatory index. It consists of a horizontal 



