Double Writing.  
THere is invented an Instrument of small bulk and price, easily made, and very durable, whereby one may in an hour's practice, write two Copies of the same thing at once, with great advantage above the ordinary way, and in a few days further use thereof, recover the former fairness and swiftness of hand, in what character soever, and whether in a Book, parchment or paper, the said writings ought to be made.  
The which Instrument shall be discovered unto Contributors, by the first day of April. 1649. at the furthest, or so soon before, as a competent reward shall be collected, the which (if men please,) may be done within less than three month's time, for the consideration of five shillings present payment; (both for the discovery and licence to practise the same during the whole fourteen years' term of the privilege,) besides two shillings and six pence for the Instrument, from such as desire that the same should be made ready for their use, by the very time of Publication.  
Which price the Inventor is content to accept (to the end that even those who shall have least need of this invention, may have no reason to complain, nor have any motive to incur the danger of the penalty allowed by the ordinance, for using the same without licence, as also in consideration, that the said sum is to be presently paid, until that after discovery, (when men shall by their own trial and experience be fully satisfied of the commodities of this faculty,) the Inventor may with more reason expect a larger reward, and more proportionable to the benefit, which each man may receive by the same; Wherefore such as please to be partakers thereof, are desired to pay the said sums either to such as the Inventor hath desired to receive them, or to himself at  

An Extract of the Ordinance of Parliament dated 6. Martii. 1647.  
THe Lords and Commons assembled in Parliament having by several certificates from divers credible men received satisfaction, not only of the feasibility, but also of the great use of the Invention for Double Writing, lately discovered by William Petty, Do ordain that the said Inventor shall have the sole benefit thereof for 14. years, according to the Statute in that behalf made, either by teaching or otherwise discovering the same, or by the sale of such Instruments as are requisite to the practice of the said Art, strictly forbidding unto all persons whatsoever the use or sale of any of the said Instruments, or practice of Double Writing upon any other Instrument, without the Licence of the said Inventor or his Assigns, upon the penalty of one hundred pounds. And do further ordain that Letters Patent be passed under the Great seal to the same purpose.  
There is also printed a Declaration concerning Double Writing, whereunto all men are referred for further satisfaction in the feasibility and facility of the Art, Time of discovery, price, and all other particulars, and circumstances relating thereunto, whereunto also is annexed a true Copy of the Ordinance of Parliament granted unto the Inventor for the sole benefit thereof; And are to be sold by R. W. at the star under Saint Peter's Church in Cornhill.