114 Machine for measuring a Ship's Way hy the Log Line. [Feb. 



"As the log line is in general use for measuring a ship's way^ 

 it is evident that so inadequate a method of ascertaining the por- 

 tion of time required must introduce many errors into the esti- 

 mate made of the velocity and progress of the vessel; and a 

 small, simple, and correct machine that can be depended upon 

 ibr this purpose appears to be a very desirable improvement. 



** A small machine which I have invented, and which has had 

 the decided approbation of many naval officers, appears to pos- 

 sess every requisite for the purpose to which it is intended to be 

 applied. It is enclosed in a round brass box, three inches and a 

 half in diameter, and one and a half in depth. It has a dial, the 

 circumference of which is divided into GO parts. In the centre 

 is an index, which is carried round by the machine once in 60'^, 

 or one minute. At the 15th, 30th, 45th, and 60th second, are 

 holes made in the dial through which pins are pushed up or down 

 by small buttons on the outside. The dial is covered in by a 

 strong glass. 



** When the machine is used, being wound up, the index is to 

 be retained at 60'' by putting the pin up at that division. If 

 then 15'' are to be counted, the pin at 15" is to be put up, and 

 the moment the log is delivered, that at 60" depressed ; the 

 index immediately advances, and continues in motion until 

 stopped at 15". If 30", or 45", or 60", are to be told, the pin 

 belonging to the number required is to be put up, and the time 

 told as before. 



" The beats of the machine can be heard at a considerable 

 distance, and the moment at which it stops so readily distin- 

 guished that it may be used as well in a dark night as during 

 day, or by a hght ; and as it is perfectly accurate, very strong 

 and very portable, it seems well adapted to supply the place of 

 those incorrect minute glasses at present in use aboard on all 

 ships." 



I think it, however, a duty incumbent on me to observe, that 

 Rear-Admiral Lowenom (a gentleman who as a hydrographer, 

 in his capacity as Chief Director of the Royal Marine Chart 

 Archives, has been of essential service to mariners ; and besides 

 this, has caused great number of lighthouses to be erected upon 

 the Danish coast, &c. &c.) had already conceived this very idea 

 several years before, and was the immediate cause of the con- 

 struction of a watch by an artist, by the name of Sparrevogn, 

 who in the year 1804 constructed a portable log watch m the form 

 of a common watch, which the person employed in logging may 

 conveniently carry about his neck, suspended by a ribbon, or in 

 any other manner. In the very moment, the first mark of the 

 log line has run out of the man's hand, he needs only to 

 press upon a spring of the watch, which directly sets it going, 

 and the index shows exactly the full seconds. When the index 

 of the watch points on to the 14th second (which serves to denote 

 one-quarter of a minute), this watch strikes a bell loudly in th« 



