414 Progress in Science. [July, 
electro-magnet in the organ, the armature of which is attached to the lever 
valve of a pneumatic pallet of peculiar construction. On pressing a key an 
electric current is completed around its corresponding magnet, and the 
armature being attracted causes the pallet to open and admit wind to the 
pipes; immediately the key is released the current ceases, the armature 
returns, and the pallet is closed. Powerful west gallery organs may thus be 
played from the east end of the church entirely through a cable of insulated 
wire an inch in diameter, or attached to additional manuals provided for that 
purpose at a mechanical organ placed close to the choir. The eleétric current 
is supplied from four cells of a single fluid battery, the electrodes of which are 
automatically withdrawn from the exciting fluid when the wind is out of the 
organ. 
The processes of envelope manufacture are among the most interesting 
exhibits, chiefly by Messrs. Goodall and Son, and by Messrs. John Dickinson 
and Co. The process commences at the northern end of the gallery, where 
the paper, as it arrives in endless rolls from the mill, is fixed to the cutting- 
machine to be cut into sheets of the required size. The paper has next to be 
‘‘olazed.” This is done by interleaving it sheet by sheet with plates of zinc 
or brass, and passing it in small quantities between rolls under enormous 
pressure varying from 20 to gotons. Out of this paper the ‘‘ blanks” of the 
required size are punched, and then have to be gummed on the ‘‘ nose,” that 
portion which has to be wetted when fastening the finished envelope, 4000 
envelopes being gummed in one hour. The blanks have now to be folded, an 
operation effected by means of machinery. 300,000 envelopes can be com- 
pleted weekly. 
About three o’clock daily the centre of interest is the Marinoni machine, 
printing the ‘“‘ Echo” newspaper at 12,000 copies per hour. The printing- 
press is the consummation of scientific principle, and we regret not being 
able to afford space for the description of the many admirable inventions. 
We must, however, record the endeavours of Mr. Walter, M.P., to attain the 
best form of ‘‘ perfecting”? machine, or one that prints both sides of the sheet 
at asingle operation, in order to dispense with the manual skill required in 
other machines to lay on sheet after sheet with the requisite accuracy. The 
Walter press requires but two attendants, and the paper passes continuously 
through the machine. At one end of the machine is placed a reel of tightly- 
rolled paper, in the form in which it leaves the paper-mill, nearly four miles 
in length. The paper is led from the reel into a series of damping cylinders, 
and thence between the first and second of four cylinders raised perpen- 
dicularly above each other. The top cylinder is encircled by the stereotype 
casts of four pages of type, whilst round the lowest of the four cylinders are 
the stereotypes of the remaining four pages of the newspaper. The paper is 
thus printed first on one side and then on the other. Passing to other cylin- 
ders, the continuous sheet is cut into lengths, each forming a complete news- 
paper. 12,000 copies of the complete paper can be printed in one hour. It 
should be said that it is to Mr. Walter that we owe much of the progress in 
printing. 
We understand upon authority that no ‘Official Report upon Recent 
Scientific Inventions and New Discoveries” will be published this year. 
