360 Venlilatioti of Coal-minea. 



l^rication of pertain species of bricks, the luauufacttire of which 

 has failed with us ? ^ 



2d. Is it possible, from satisfactory experiments, or reasons 

 deduced from the doctrine of determinate proportions, to esta-r 

 blish with certainty that tlie radical of nuiriatic acid is a compound 

 bodv; or is it more probable that the radical is a simple body ? 

 In case of no decision on the question, Wliich of the two methods 

 (experiment or doctrine of determinate proportion?) is best yalcu- 

 iated to simplify the theory of chemical l^icts } 



3d. The printing paper of France, and drawing paper fabrir 

 cated in England, having an asjknovvledged superiority above those 

 of other countries, it is required to know in what that superiority 

 consists ? — whether the causes are of a local nature, or depend on 

 the materials or mode of manufacture ? 



4th. What is the quantity of water discharged by a river at a 

 given place, and during a fixed period of time, the breadth, the 

 depth, and def.llvity of the river being known ? — and what are 

 the variations which, at the same point, and during the same 

 space of time, will take place in that discharge, by diminishing 

 progressively, by artilicial constructions, the breadth of tiie river? 



The prize for each of these questions is to be a gold medal of 

 the weight of twenty-five ducats. The memoirs to be written in 

 Latin, French, Dutch, or German, and given in— those on the 

 first three Cjuestions, before the- 1st February ISIS, and that on 

 the last, before the 1st Nov. iSlS. 



XC. InteUigence and Misceliaueous Articles. 



^ VENTILATION OF COAL- WINES. 



A PAPER on the ventilation of coal-mines, Avith a plan of the 

 present mode of ventilation, and a plan of a proposed iinprove- 

 ir.ent, have been received. It may appear presumptuous in any 

 one not a colliery-viewer, to form even an opinion on the modes 

 best adapted for ventilation; but, notwithstanding, we have formed 

 an opinion, and we are convinced that the method usually fol- 

 lowed at Newcastle is not the best that might be adopted. The 

 paper that has reached lis might improve the systeni a little ; 

 but till we sec some demonstration of tiie inefficacy ot that pro- 

 posed by Mr. Ryan, we think it would be wrong in us to lent! 

 our aid to recommend others less effectual. It is asserted, tliat 

 any one of the mines at Newcastle might be properly ventilated 

 on his plan, at an expense under 100/. A mere denial of the 

 fact, and much less silence, on a subject involving the safety of 

 80 tnany lives, will not convince those who have examined this 

 subject, that the managers of mines at Newcastle can be justi- 

 fied in any longer refiising to be instructed. 



' STBAM 



