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New process for photo-lithography
320
Mechanics, _Pl~ysies, and Cl,emistry.
through a snow storm; there were many spieul~e, and eross-spicul~e, with snow crystals small in size, but distinct ; there were few, if any, flakes ; as we descended the snow seemed to rise above us. At 2 h. 17 m. we passed below the regions of snow, and shortly afterwards we saw a canal and then another, each being straight for miles apparently. The state of" the lower atmosphere was most remarkable : Mr. Coxwell had never seen it so murky before ; when far from a town, it was of a brownish, yellowish tinge, and remarkably dull. No distance on land could be seen. When at the height of I mile, we had no more sand, and simplybecame a falling body, checked somewhat by the balloon; we threw away leaden weights, &c., to help check the rapidity of descent. The ground wind was strong, and the descent was somewhat rough ; we rebounded from the earth three or four tilncs, and finally the grapnel caught in a water-course. Photographic papers of two kinds were taken up, the one prepared with iodide of silver, and the other wit}l chloride of silver, and arrangements were made that both kinds, parts of the same sheets of paper, should be observed at Greenwich in the first minute of every five minutes from noon to 5 o'clock. The comparison of results show all much deeper colors at Greenwich at first, but the sky at Greenwich was not cloudy for three hours af.ter it was overcast at Wolvcrton, but coloration of both kinds of paper under a cloudy sky was very nearly the same as that in tile balloon. JA~IES GLAISItER. 1)dackheath, July 6th, 1S(3.
TransI~ted for the Journal of the Franklin Institute.
.New _Processfor -pltoto-litltograp]ty. M. Morvan is the inventor of the following process, by which all kinds of drawings and engravings, whether manuscript or printed, may be reproduced on stone simply and rapidly. The stone is first covered by tile pencil with a thin coat of a varnish composed of 50 grammes of bi-chromate of amlnonia, 300 gramrues of albumen, and 300 grammes of water. When the surface is dry, it is exposed to the light under the object which is to be reproduced. The time of exposure depends upon the opacity of the object and the intensity of the light ; but as a mean, we may say, that it will require from two to three minutes in full sunshine, and ten minutes in the shade. When the object is removed from the surface of the stone, which must be done in a dark room, nothing is seen upon the surface; but if the stone be washed with white soap, the soluble parts (that is those which have been protected from the light) are washed away and the stone is slightly eaten away in the parts thus exposed; while, wherever the light has been felt, the oxide of chrome formed by its action resists the corrosion of the soap; thus the image appears. In inking, the surface of the stone is first covered by a thin sheet of water, and the inking roller charged with the fat-ink passed over it; the ink can only adhere in the hollows, it is repelled by the water on tho
International Exhibition--Jurors' Report on ,Machinery.
321
reliefs ; the hollows therefore furnish the shadows and the reliefs the lights of the impression ; and as these reliefs were the lights and the hollows corresponded to the shadows of the original picture, it will be seen that a positive and direct copy is formed, and the original is in nowise injured, since it was laid upon the dry surface of the stone. By allowing the soap to remain upoa the stone the impression is made deeper and the depth can be made to suit our purposes, the ordinary time is, about a quarter of an hour, after which we m~y proceed to printing. M. Morvan exhibits m~ps, writings, and pen-drawings, photographic proofs, &c,, copied by this process, which seem to dc,monstrate that the process is a valuable improvement.--Cosmos.
fnternational Exhibition, 1S62.--Juror,~' lleport. Frmn the Lon,1. Cir. Eng. aml .~rch. Journal, N,w., 1~;62. IN GENERAL. Subdivision I]-. Separate _Parts of M~,~eIdm% ~,)~eeimcns of IVorlo~ta~s/dl) , it[iscellaneous 2ieces of 3ffeehanism.
CLASS Y I I I . - - M A C I I I N E R Y
( C o n t i n u e d f r o m p. 1,~,%)
SECTmN I.--Heavy Castings or Forgb~gs in the Ro'uffh ; Caslings or Forgings, plain, intricate, or be,outiful, in the rouffh.--As compared with articles under these heads exhibited in 1851, we consider there is a decided improvement; few, however, are exhibited in this class as abstract specimens, but are for the most part portions of machines: there are nevertheless some excellent specimens of forgings of very large dimensions, and which owe their excellence in finish nnd soundness, mainly, to the facility afforded in their construction bv the application of the Nasmyth and other steam hammers : some of'the large forged shafts are put together in longitudinal segments, which is another reason for their soundness. A complete revolution in the manufacture of large forgings has been effeeted by the steam hammer. The castings of large marine engine cylinders attd other parts, the crank shafts, eross-he:~ds, connecting rods, &c., in wrought iron, as shown in the present Exhibition, are such as never were produced of equally good quality ou any fi)rmer occasion. Fr. Krupp, Essen (Prussia--1308).--This exhibition includes the ]~rgest block of steel in the Exhibition ; also some excellent specimens of east steel axle-trees, and other first-rate specimens of steel manut~tcture. Medal awarded for excellent workmanship and material, practical success, general excellence. iISder Mining and Forging Company (Prussia--1258).--Wheel forgings, locomotive tires of puddled steel, wrought iron telegraph poles, &c. I[o,mrable mention, very good work. Petrarsa Royal Works (It:dy--1058).--.k htrge wrought iron shaft for screw propeller, very good specimen of plain forging, l[onorablo mention. Under the above heads, the Jury wish to cull attention to a beauti-
Mechanics, _Pl~ysies, and Cl,emistry.
through a snow storm; there were many spieul~e, and eross-spicul~e, with snow crystals small in size, but distinct ; there were few, if any, flakes ; as we descended the snow seemed to rise above us. At 2 h. 17 m. we passed below the regions of snow, and shortly afterwards we saw a canal and then another, each being straight for miles apparently. The state of" the lower atmosphere was most remarkable : Mr. Coxwell had never seen it so murky before ; when far from a town, it was of a brownish, yellowish tinge, and remarkably dull. No distance on land could be seen. When at the height of I mile, we had no more sand, and simplybecame a falling body, checked somewhat by the balloon; we threw away leaden weights, &c., to help check the rapidity of descent. The ground wind was strong, and the descent was somewhat rough ; we rebounded from the earth three or four tilncs, and finally the grapnel caught in a water-course. Photographic papers of two kinds were taken up, the one prepared with iodide of silver, and the other wit}l chloride of silver, and arrangements were made that both kinds, parts of the same sheets of paper, should be observed at Greenwich in the first minute of every five minutes from noon to 5 o'clock. The comparison of results show all much deeper colors at Greenwich at first, but the sky at Greenwich was not cloudy for three hours af.ter it was overcast at Wolvcrton, but coloration of both kinds of paper under a cloudy sky was very nearly the same as that in tile balloon. JA~IES GLAISItER. 1)dackheath, July 6th, 1S(3.
TransI~ted for the Journal of the Franklin Institute.
.New _Processfor -pltoto-litltograp]ty. M. Morvan is the inventor of the following process, by which all kinds of drawings and engravings, whether manuscript or printed, may be reproduced on stone simply and rapidly. The stone is first covered by tile pencil with a thin coat of a varnish composed of 50 grammes of bi-chromate of amlnonia, 300 gramrues of albumen, and 300 grammes of water. When the surface is dry, it is exposed to the light under the object which is to be reproduced. The time of exposure depends upon the opacity of the object and the intensity of the light ; but as a mean, we may say, that it will require from two to three minutes in full sunshine, and ten minutes in the shade. When the object is removed from the surface of the stone, which must be done in a dark room, nothing is seen upon the surface; but if the stone be washed with white soap, the soluble parts (that is those which have been protected from the light) are washed away and the stone is slightly eaten away in the parts thus exposed; while, wherever the light has been felt, the oxide of chrome formed by its action resists the corrosion of the soap; thus the image appears. In inking, the surface of the stone is first covered by a thin sheet of water, and the inking roller charged with the fat-ink passed over it; the ink can only adhere in the hollows, it is repelled by the water on tho
International Exhibition--Jurors' Report on ,Machinery.
321
reliefs ; the hollows therefore furnish the shadows and the reliefs the lights of the impression ; and as these reliefs were the lights and the hollows corresponded to the shadows of the original picture, it will be seen that a positive and direct copy is formed, and the original is in nowise injured, since it was laid upon the dry surface of the stone. By allowing the soap to remain upoa the stone the impression is made deeper and the depth can be made to suit our purposes, the ordinary time is, about a quarter of an hour, after which we m~y proceed to printing. M. Morvan exhibits m~ps, writings, and pen-drawings, photographic proofs, &c,, copied by this process, which seem to dc,monstrate that the process is a valuable improvement.--Cosmos.
fnternational Exhibition, 1S62.--Juror,~' lleport. Frmn the Lon,1. Cir. Eng. aml .~rch. Journal, N,w., 1~;62. IN GENERAL. Subdivision I]-. Separate _Parts of M~,~eIdm% ~,)~eeimcns of IVorlo~ta~s/dl) , it[iscellaneous 2ieces of 3ffeehanism.
CLASS Y I I I . - - M A C I I I N E R Y
( C o n t i n u e d f r o m p. 1,~,%)
SECTmN I.--Heavy Castings or Forgb~gs in the Ro'uffh ; Caslings or Forgings, plain, intricate, or be,outiful, in the rouffh.--As compared with articles under these heads exhibited in 1851, we consider there is a decided improvement; few, however, are exhibited in this class as abstract specimens, but are for the most part portions of machines: there are nevertheless some excellent specimens of forgings of very large dimensions, and which owe their excellence in finish nnd soundness, mainly, to the facility afforded in their construction bv the application of the Nasmyth and other steam hammers : some of'the large forged shafts are put together in longitudinal segments, which is another reason for their soundness. A complete revolution in the manufacture of large forgings has been effeeted by the steam hammer. The castings of large marine engine cylinders attd other parts, the crank shafts, eross-he:~ds, connecting rods, &c., in wrought iron, as shown in the present Exhibition, are such as never were produced of equally good quality ou any fi)rmer occasion. Fr. Krupp, Essen (Prussia--1308).--This exhibition includes the ]~rgest block of steel in the Exhibition ; also some excellent specimens of east steel axle-trees, and other first-rate specimens of steel manut~tcture. Medal awarded for excellent workmanship and material, practical success, general excellence. iISder Mining and Forging Company (Prussia--1258).--Wheel forgings, locomotive tires of puddled steel, wrought iron telegraph poles, &c. I[o,mrable mention, very good work. Petrarsa Royal Works (It:dy--1058).--.k htrge wrought iron shaft for screw propeller, very good specimen of plain forging, l[onorablo mention. Under the above heads, the Jury wish to cull attention to a beauti-