Machinery xvUh the Manual. flW(|^^ IfrCASt- 859 



Should a press be nt any time unemployed, therp js c^qspfinliirply UUic 1<)9% 

 for the first cost is not great, an<l there are no men's wages to pay in the in» 

 terim ; hut the very reverse is the case with a printing machine, the original 

 outlay for one, independently of that for the engine, &c., being from L. 400. to 

 Ij. 700, and a considerable subsequent expense of keeping in repair, and a 

 stated rate of wages to one man and two boys at least. Ilence it is evident 

 that common presses must uf necessity continue to be in much more general 

 use than printing machines, and could Mr Clerk Maxweirs ingenious improve- 

 ment upon the presses ]>e carried into effect, there is no doubt of their value 

 and utility being very greatly increased, liy it, not only would the labour 

 of one man at each press be entirely saved, but that of the other be alfso re- 

 duced to little more than supplying the sheets of paj>er. The quality of the 

 work, too, from the regularity of inking and pressure, would be much im- 

 proved, and means would undoubtedly soon be fallen upon for increasing or 

 diminishing the quantity, in a given time, according to the nature of the work 

 in hand. There would certainly be the additional expense attendant upon 

 an engine, Sec. for each printing oflice, which there is not at present : but 

 surely if the same kind of mechanical i)ower be found more economical and 

 advantageous than manual labour for colTeei-grinding, and similar purposes^ 

 it would be much more so if it could be rendered applicable to the important 

 operations of miscellaneous letter-press printing. In short, it is very evident 

 that the demand for printing presses and self-inking apparatuses of the kind 

 contemplated would be every where very great> and would soon amply remu^ 

 nerate any one, whether in Europe or in America, who might be so fortunate 

 aa to bring them first into efiective and economical operation. 



Account of a Platina Lamp, By Gkorgk MERRYWEATHEir, 

 Eiiq. of Whitby. In a Letter to Professor Jameson. {WilFi 

 a Plate.) 



A FEW years ago, Sir Humphry Davy made the discovery, 

 that, if a coil of small platina wire be placed around the wick 

 of a spirit lamp, and rendered red-hot, the wire would continue 

 ignited for a length of time, after the flame was blown out. In 

 consequence of having lately witnessed this singular phenomenon 

 at Professor Hopc''s lectures, and that it was generally viewed 

 as nothing more than an amusing experiment, I was induced to 

 give the subject some attention, as I felt convinced that a mode 

 might be devised of turning it to some useful purpose. 



Ot^'il^ 8d of last mouth, I contrived an apparatus ; but not meetinj^ with 

 the success I expected with platina wire, I made use of spongy pfatinn, which 

 I found to answer the object I had in view. In of der that a correct idea may 

 be formed, I have nunde a drawing of this apparatus. The Iqwer port is coo. 



