VOL.. XIV. NO. 48. 



AND GARDENER'S JOURNAL. 



381 



HOT AIR Bl,\ST, 



We copied into this paper about n year since 

 fioni the .Journal of the Kranlxlin Institute, son:e 

 notices of the upplioution of the hot air blast in 

 smeltinj; furnaces, by iron masters in France anil 

 Scotland. From these it appeared that important 

 advantages in economy of fuel, were found to re- 

 sult from heating to a high temperature the air 

 enjoyed in alimenting the furnace previously to 

 introduction into the stack. We are happy to be 

 able to announce that the infornuition thus afford- 

 ed has been acted upon by tlie enterprising iron 

 master of our own neighborhood, with such de- 

 cided success that his example has been followed 

 by at least one other gentleman engaged in the 

 same business, and that others are now making 

 arrangements to avail tliemselves of the benefits 

 wbicli experience has shown to attend the im- 

 provement thus adopted. Major John Schwartz, 

 the [)roprietor of Mount Penn Furnace, on the 

 other side of the Schuylkill, about three miles from 

 the town of Reading, Pennsylvania, is we believe 

 entitled to the credit of being the first American 

 iron master who has ventured to depart from the 

 beaten track and employ a new invention, likely 

 as it appears from the result, to be of the highest 

 importance, both to the makers and consumers of 

 iron in the United States. We got an invitation 

 last week to visit the furnace and witness its op- 

 eration, and were enabled with Major Schwartz's 

 explarations to understand the manner in which 

 the improvement is applied, and to appreciate the 

 advantages which result from its introduction. The 

 simplicity and economy of the means by which 

 the air is heated, are considerations of no small 

 importance in the adoption of a new invention 

 which might have obtained but few friends, if ex- 

 pensive and complicated machinery were indis- 

 pensable to its enjoyment. 



It occurred to Major Schwartz, that the fire of 

 the furnace itself, which day and night was send- 

 ing forth tall flames and wasting its heat upon 'the 

 desert air, might be advantageously used in im- 

 parting the necessary degree of temperature to 

 the air which issued from his bellows. Accord- 

 ingly by means of additional pipes he conducted 

 the air from the moutli of the bellows to the trun- 

 dle head at the mouth of the stack, where being 

 passed many times cross the flame and protected 

 by an oven constructed for that purpose, it was 

 found to be heated to the temperature of melted 

 lead, which is something over six hundred degrees 

 of Fahrenheit. Thus heated the air in conducted 

 downwards again into the furnace room and sub- 

 jected to the heat of an oven supplied with refuse 

 charcoal, witli the view of restoring any heat which 

 may have been lost during its passage from the 

 top to the bottom of the stack. Passing through 

 this oven the air reaches the tuyere and is applied 

 to the charge in the furnace in the usual manner, 

 but heated to a temperature of between five and 

 six hundred degrees. By this simple operation, 

 which is not attended by increase of current ex- 

 penses to the amount of a single dollar, upwards 

 of twenty per cent is saved of the fuel necessary 

 to keep the furnace going. The cost of the whole 

 apparatus with the expense of erection, we are 

 informed, does not exceed three hundred dollars. 

 Iron masters will understand better than we can 

 the advantage obtained in point of economy, from 

 the facts stated to us by the persons employed 

 about the works relative to the performance of the 

 furnace. They told us before the air was heated 



seven baskets of charcoal were iiccess iry to fuse 

 from thirteen to fifleen boxes of ore, but that at 

 present they arc able to work from filUien to sev- 

 enteen with five baskets of charcoal. Judge Dar- 

 ling, who has introduced the hot blast at Joanna 

 Furnace, since the successful experiment of Ma- 

 jor Schwartz, Jiinks the (piantity of iron has in- 

 creased about four and a half tons per week with 

 the same amount of fuel, which is again of about 

 twentyfive per cent. The expense of his appara- 

 tus did not exceed two luindred dollars. Besides 

 the saving of fuel it is thought that the quality of 

 the iron is improved, and that the castings are more 

 perfect in consequence of the cotnplL-te liquefac- 

 tion of the metal by the increased heat. The iron 

 made at Mount Penn is used principally m the 

 manufacture of nails, and the opinion of Major 

 Schwartz is, that it does not deteriorate in conse- 

 quence of heating the air, but that it is decidedly 

 improved in quality. Furnace men are obliged 

 to watch the stacks with care, to see that the ne- 

 cessary temperature is kept up.and that the iron 

 does not chill in the furnace and become intract- 

 able, so as to require a great increase of fuel and 

 diminution of ore. 



One great advantage derived from heating the 

 air is, that the danger of chilling the Furnace is 

 almost entirely removed, and that when the tem- 

 perature does decline to too low a grade, a small 

 dimunition of the quantity of ore is sufficient to 

 raise it. The men at the works informed us that 

 a considerable saving of labor is found to result 

 from the introduction of this improvement, and 

 ever one appears to agree with the proprietor as 

 to the advantages already mentioned. It seems 

 to us, now, that we have witnessed the success of 

 this experiment, and observed the simplicity with 

 which the improvement is applied, that it ought 

 to have been discovered years ago. The iron 

 business is a pretty old one, having existed, no 

 doubt before the siege of Troy, so that ample time 

 has been allowed to give tlje subject all the con- 

 sideration it would seem to require. 



We all know that atmospheric air is indispen- 

 sable to combustion, and that fire cannot be main- 

 tained for a moment without it. But then as 

 worthy Tom Thornton would say, "too much 

 water drowns the miller," and too much air instead 

 of increasing a fire, is very apt to put it out. Every 

 body has experienced this or may easily do so, by 

 trying to mend an anthracite fire with a pair of 

 bellows. The cause as we understand it, is that 

 the cold air blown into the fire reduces the tem- 

 perature below the degree at which (he fuel will 

 burn. If so, it must be obvious enough, that if 

 you could heat the air before you apjilied it to the 

 fire, the mischief would be remedied at once. It 

 seems singular, therefore, that no one until lately 

 should have thought of warming the air which is 

 blown perpetually into the stack of a furnace at 

 twenty degrees below zero, when the weather is 

 cold enough to reduce it to that point. We niight 

 be told perhaps, that it is very easy to prophecy 

 after the event, and that the wisdom of finding out 

 the facility of a discovery made to your hand, was 

 illustrated long ago by the story ot Columbus and 

 the egg. To return to our subject. — It has been 

 BUtBciently proved that great advantages flow from 

 heating the air to five or six hundred degrees, and 

 how much higher it can be healed with propor- 

 tional advantage, is left for the ingenuity of those 

 who are interested in this important subject 

 to discover — Berks and Schuylkill Journal. 



MRIUOIR OF Sr^ATEa AIVD HISTORY OP 

 MANUPACTUUKS. 



Some time .since we announced that a gentle- 

 man (the Rev. George S. White) was preparing 

 for the press a biography of the late Samuel .Sla- 

 ter, F,s(|. ofKhode Island, the father of the Amer- 

 ican Mantiliiclures. The work is now complete, 

 and we have a copy before UH in octavo, hand- 

 somely printed and illustrated by n great num- 

 ber of plates. 



The '' j^Ieirjoir of Slater" is connected with the 

 history of the rise and progress of Manufactures, 

 and includes notices of llargravc:, Arkwrighl, 

 Strutt, Cromphon, Cartvvright' of England ; and 

 Coxe, Wetherill, Fitch, Evans and Fulton, of 

 America, descriptive of the C'arly manufacture, and 

 the growth of Cotton. The frontispiece is a steel 

 engraving of the father of our mauufactures, and 

 is pronounced an excellent likene-ss. 



The/ac simile of his Indenture with Mr Strutt 

 is an interesting document. 



There are thirty engravings, and ten very im- 

 portant ones on silk machinery, containing the 

 latest improvements, as prejiared by Dr. Ure. 



Iti an introductory chajiter the author has taken 

 a condensed retrospective view of the restrictions 

 on trade imposed on the coloni-es, to which co- 

 lonial policy of Great Britain be attributes the 

 war of the revolution, 



Tho chapter oa the Moral Influence of Manu- 

 facturing EstablishmeHts, is a triumfihant state- 

 ment of fects, which removes all previous appre- 

 hensions and objections to the system of manufact- 

 uring for ourselves. This documentary evidence 

 is most conclusive, as to I he prosperous and moral 

 condition of oiir manufacturing establishments. 

 The introduction of the Power Loouj, and of the 

 Calico Printing, forms a new era in the business ; 

 and it is stated that 120 millions of yards of Calico 

 havo been printed in this country the last year. 

 A description of new machinery for the manufac- 

 ture of WoKsted,. we should think well worthy the 

 attentionof woolen manufacturers, as we are ca- 

 pable of making great i^nprovements, and of in- 

 creasing the roaijufacture of worsted in a great 

 variety of articles. 



The present state and progress of manufactures 

 is most encouraging. An article on the subject 

 of wages, places that subject in a true light: — 

 and a vi.ew of the comparative advantages between 

 America, England, France, &c. with regard to 

 the facilities and capabilities for manufactures of 

 all descriptions, is highly flattering to our favored 

 situation. 



Every subject connected vvith the philosophy of 

 manufacture, is niore or less referred to and dis- 

 cuss d in this volume. 



The profile likeness of that old jiatriot, Samuel 

 Wetherill, must be highly gratifying to his imme- 

 diate descendants, as well as to the cotnnmnity at 

 large, 



Numerous extracts are made from the writings 

 of Tench Coxe, as well as the original letters to 

 him from Fisher Ames, Jay, JeflTerson, Hamilton, 

 &c. which exemplify his indefatigable exertions in 

 the development of the resources of the country. 



The Biography of Slater is composed from ma- 

 terials afforded by the family, and fioni the au- 

 thor's acquaintance with th seubjectof his memoir, 

 and reflects credit upon the talents and industry 

 of the author. 



The work is foi- sale by Messrs Kay & Brother, 

 Chesnut below Fourth. — U. S. Gax. 



