542 LETTERS 
ufual certificate of the enrolment indorfed on it; this is 
commonly done in about a week or a fortnight afterwards; 
and then the patent is in every refpeft complete. 
Agreeably to the terms of the patent, the patentee, 
within a limited time after its date, commonly, though 
not always, one calendar month, is particularly to defcribe 
and afcertain the nature of his invention, and in what 
manner the fame is to be performed. The objeft of 
which is to publifh the invention, for the benefit of the 
public, at the expiration of the patent granted as the 
patentee’s reward for the difcovery. The inftrument de- 
fcribing and afcertaining the nature of the invention, and 
in what manner it is performed, is named the fpecif cation. 
And, if any material part of it be falfe, or only ambigu¬ 
ous, the patent will be void. Therefore, where the pa¬ 
tent was for making a particular fort of yellow-, and the 
patentee directed any kind of foflil fait to be ufed, when 
only one fort of it would anfwer the purpofe, the patent 
was held void. So it was where the patent was for Heel 
trulfes, and the patentee had omitted what was of ufe in 
tempering the Heel, namely, rubbing it with tallow-. So 
if an article of no ufe be inferted, that will likewife viti¬ 
ate the patent. Indeed, the patentee mult defcribe his 
invention, in the moft clear and unequivocal terms of 
which the fubjeft is capable; therefore, if the procefs, as 
directed by the fpecificatiotr, do not produce that which 
the patent profelfes it to do, the patent will be void. For 
the invention Ihould be fo defcribed, that perfons in the 
fame line may thereby perform the thing invented, it be¬ 
ing incumbent on the patentee, fo clearly to defcribe the 
invention, that any man of fcience need not refort to ex¬ 
periments, but may be able to do the thing for which 
the patent is granted, by merely following the directions 
of the fpecification. And not only the thing invented 
mull; be defcribed, but the relation of the feveral parts, 
and the union of the whole, where complex mechanifm 
is the objeft of the patent. Befides which, the patentee 
mult fo defcribe his invention, that the public may, after 
the expiration of the patent, have the ufe of it as benefi¬ 
cially as the patentee himfelf had before. 
If the patent be in all points good, and any perfon in¬ 
fringes on it, the patentee may either bring an aftion at 
law, for damages, or file a bill in equity, for an account 
of the profits made from the illegal ufe of the invention, 
and thereupon obtain an injunction to reftrain the party 
from the further ufe of it; but there mull be feparate bills 
upon every diftinft invafion of the patent. On the trial 
of the adtion for damages, the patentee muft give fome 
evidence, though (light will be fufficient, to (how the na¬ 
ture of his invention, and in what it confiits, and that he 
produced the eft'eft, propofed by the patent, in the man¬ 
ner fpecified ; and then it is incumbent on the other party 
to falfify it. Here we may add, that, if the patentee 
wifiies the trial to be at the Weftminfter fittings, the party 
complained againlt will not be permitted to remove it to 
any other place. 
If an inventor be not prepared to apply for a patent for 
his invention, and w-ifhes effectually to prevent its being 
purloined from him, he (hould enter what is called a ca¬ 
veat, againlt any patent being granted, which, he thinks, 
may intrench upon his invention. The mode of enter¬ 
ing" the caveat, and the effect of it, is this: A requejl is 
left at both the attorney and folicitor general’s chambers, 
defiring notice of any application for fuch a patent. This 
requelt, or caveat as it is now called, muft be annually 
renewed; when, if any application for fuch a patent 
fhonld be made, pending its continuance, the clerk lends 
notice, in the nature of a fummons, requiring the atten¬ 
dance, at a fpecified time, of all the parties concerned, on 
the attorney or folicitor general, whichever it comes from. 
Both parties then attend accordingly, with their folicitors, 
and models, drawings, or other explanations, of their in¬ 
ventions; and, upon the infpeCfion of them, the attorney 
or folicitor general decides whether the inventions are the 
fame. If they are different, each party will haye his pa- 
5 
PATENT. 
tent as a matter of courfe. But, if it appears to be one 
invention, he then decides, on hearing both parties, to 
which of them, in his opinion, it belongs, and reports ac¬ 
cordingly. If the party is diffatisfied with his decilion, a 
fimilar caveat (hould then be entered at the chancery pa¬ 
tent-office, when, on the patent’s coming to the ^reat 
feal, the lord-chancellor will, in like manner, ultimately 
decide, whether he (hould or not permit the patent ap¬ 
plied for to be fealed. 
Though no grant by letters patent, for inventions, can 
be for a longer term than fourteen years, yet the legifia- 
ture may, and often does, prolong the term, by an aft of 
parliament; where it appears, that the patentee, on ac¬ 
count of any fpecial circumftances, will not, within the 
time for which the patent was granted, be fufficiently re¬ 
warded for making the invention or difcovery public ; or 
where, in confequence of fubfequent improvements, he 
is equitably entitled to a prolongation of the term. In 
thefe cafes, the additional terms granted depend on the 
particular circumftances, varying.from feven to fourteen 
years. The aft of parliament is obtained much in the 
manner that private afts are; but the final claufe gene¬ 
rally declares it a public aft, and to be judicially noticed 
without being fpecially pleaded. 
Laftly, though the patent contains a provifo for mak¬ 
ing it void on an affignment of it to a greater number than 
Jive perfons ; yet the legiflature will, by an aft of parliament , 
enable the patentee to make a transfer of his intereft in the 
patent to more than fuch limited number, on a fufficient 
reafon being given for the application ; as if, on account 
of the magnitude of the concern, it be expedient that 
more than the limited number of perfons (hould become 
interefted in the patent. 
We (hall infert the forms neceflary to be filled up in 
order to obtain letters-patent; and alfo of that very im¬ 
portant paper, the Specification. 
Petition for the Patent. 
To the King's Mof Excellent Majefy. 
The humble petition of R.W. of (fieweth. 
That your petitioner, after confiderable application and 
expenie, hath invented or found out [here comes in the 
title of the invention], which invention, he believes, will 
be of general benefit and advantage. That he is the true 
and firft inventor thereof, and that the fame hath not been 
made or ufed by any other perfon or perlons whomfoever, 
to his knowledge or belief. 
Your petitioner, therefore, humbly prays, that your 
majefty will be gracioufly pleafed to grant unto 
him, his executors, adminiftrators, and aftigns, 
your royal letters patent, under the great feal of 
Great Britain, for the foie working, conftrufting,. 
making, felling, ufing, and exercifing, of his (hid 
invention, and all other benefit and advantage 
thereof, within that part of your majefty’s united 
kingdom of Great-Britain and Ireland called Eng¬ 
land, your dominion of Wales and town of Ber¬ 
wick-upon-Tweed, and alfo in all your majefy's 
colonies and plantations abroad, [if the patent be 
not meant to extend to the colonies, the words in 
Italics are not inferted,] for the term of fourteen 
years, according to the ftatute in that cafe made 
and provided. 
And your petitioner (hall ever pray, See. 
[The petition to be written on undamped paper, and 
need not be figned.] 
Affidavit in fupport of the Petition. 
R.W. of maketh oath and faith, that, af¬ 
ter confiderable application and expenfe, he hath invent¬ 
ed, or found out, [here comes in the title of the inven¬ 
tion, as defcribed in the petition,] which invention, he 
believes, will be of general benefit and advantage; and 
this deponent further faith, that he is the true and firit 
inventor thereof, and that the fame hath not been made 
or ufed by any other perfon or perfons whomfoever, to 
his knowledge or belief. R. W. 
Sworn 
