科技在经济中的最大作用就是提高劳动生产率，使用同样的成本创造更多的财富。二百多年来，美国在科技进步的推动下取得了工业、农业与服务业的长足进展，积聚的强大经济实力在当今世界独占鳌头。然而在独立以前，技术进步曾一度在北美殖民地作用甚微，经济发展相对落后。尤其在对外贸易方面，敌国侵扰与海盗肆虐限制了先进造船技术的应用：为了时刻准备对付海上来犯之敌，殖民地的商船不得不加固船体，增派船员，荷枪实弹，严阵以待。这种状况大大增加了贸易成本，降低了海运效率，不利于殖民地的经济发展。

Among the most powerful engines of modern economic growth1 have been technological changes2 that raise output relative to inputs3. But compared with those of the nineteenth century4, technological changes remained minor and sporadic in the colonial period. It preceded the era of the cotton gin5, steam power6, and the many metallurgical advances7 that vastly increased the tools available to workers. Iniron production, learning by doing and adapting remained the key source of labor and fuel savings in the late colonial period — learning to reduce the fuel input to minimal levels saved on labor needed to gather charcoal8 and work the forges9. Technology remained static and forge sizes constant, however. The evidence in agriculture also indicates no significant leaps in technology ?nbsp;old ways prevailed and farming was typically stable and uniform.

In shipping, the same conclusion is reached. This period preceded the era of iron ships and steam, and both ship material and the power source of ships10 remained unchanged. Even increasingly complex sails and rigs and the alterations of hull shapes failed to increase ship speed and, in any case, did not represent fundamental advances in knowledge.

As a matter of fact, during the early 17th century, Dutch shipping11 had already displayed many of the essential characteristics of design, manning12, and other input requirements13 that were found on the most advanced vessels in the western Atlantic in the 1760s and 1770s. The Dutch first introduced the flyboat, or flute, a specialized merchant vessel designed to carry bulk commodities14. The flyboat was exceptionally long compared with its width, had a flat bottom, and was lightly built. In addition its rig was simple, and its crew size was small15. In contrast, English and colonial vessels were built, gunned, and manned more heavily to meet the dual purpose of trade and defense. Their solid construction and armaments were costly — not only in materials but in manpower. Larger crews were needed to handle the more complex riggings on these vessels as well as their guns.

It became evident that the flyboat could be used advantageously in certain bulk trades where the danger of piracy was low. However, in the rich but dangerous trades into the Mediterranean16 and the West Indies17, more costly ships were required. In general, high risks in all colonial waters led to one of the most notable features of 17th-century shipping ?nbsp;the widespread use of cannons and armaments on trading vessels. Such characteristics were still observed in certain waters throughout much of the 18th century. Until around 1750 in the Caribbean18, especially near Jamaica19, vessels weighing more than 100 tons were almost always armed and even small vessels usually carried some guns.

Privateering20 also added to the disorder. As a common practice, nation-states often gave private citizens license to harass the ships of rivals states. These privateering commissions or "letters of marque" were issued without constraint in wartime, and even in peacetime they were occasionally given to citizens who had suffered losses due to the actions of subjects from an offending states. Since privateers frequently ignored the constraints of their commissions, privateering was often difficult to distinguish from common piracy21.

Other government policies also tended to aggravate existing sea hazards. Adding to the supply of privateers and pirates, some of the islands were deliberately peopled with convicts22. Of course, piracy was not confined to the Caribbean. Pirates lurked safely in the inlets of North Carolina23, from which they regularly raided vessels trading at Charleston24. In 1718 it was exclaimed that "every month brought intelligence of renewed outrages of vessels sacked on the high seas25, burned with their cargo, or seized and converted to the nefarious uses of the outlaws." Local traders, shippers, and government officials in the Carolinas repeatedly solicited the Board of Trade26 for protection. In desperation, Carolina's Assembly appropriated funds in 1719 to support private vessels in the hope of driving the pirates from their seas. These pleas and protective actions were mostly in vain, but finally, as the benefits of assuring safe trade lanes rose relative to the costs of eliminating piracy, the Royal Navy took action. By the early 1740s, piracy had been eliminated from the western Atlantic.

The fall of piracy was paralleled by the elimination of ship armaments and the reduction of crew sizes. As such, this was a process of technical diffusion. Without piracy, specialized cargo-carrying vessels similar to the flyboat were designed, thereby substantially reducing the costs of shipping.

技术变革，可以提高产出投入比率，因而它是现代经 济增长的一个强大动力。然而，与十九世纪相比，殖民地时期的技术变革进展不大且时有中断，因为轧棉机、蒸汽机以及许多冶金方面的进步大大增加劳动者所用工具的时代还没有到来。在炼铁方面，殖民地后期劳动力与燃 料的节省主要是通过在劳动中学习和不断适应得到的——学会最低限度地使用燃料，节省了采集木炭和清理炉具的人力。但是，生产技术毫无变化，锻炉规模也一成不变。在农业方面，也无重大技术进步可言——旧工艺依然盛行，耕作内容也基本固定，没有变化。

在海运方面，结论也是如此。由于铁制轮船与蒸汽船的时代尚未到来，所以造船材料与轮船动力没有改变。尽管船帆、桅杆越发复杂，船体形状也不断改进，但不足以提高船速，无论如何也代表不了技术知识的根本性进步。

实际上，早在17世纪初，荷兰的海运业就在设计、人员配备及其他要素投入上显示出诸多重要特点——这些特点在18世纪60、70年代大西洋西海域最先进的轮船上就能看到。当时荷兰人推出了快艇，或称平底凹槽船，一种为运输大宗货物特别制造的商船。这种快艇船身长度大大超出其宽度，底平，体轻。此外，其桅杆简单，船员少。相反，英国与殖民地的轮船则在船体、武器装备及人员配备上加大份量，以满足防御与贸易的双重需要。这种坚固的构造与武器装备在建材以及人力上耗资都较大，因为操纵复杂的桅杆与枪支需要增加更多的船员。

显而易见，快艇适于海盗劫掠可能性低的地区的一些大宗贸易使用。而地中海与西印度群岛地区赚头大而风险高的贸易则需要造价昂贵的轮船。总的说来，整个殖民地水域的高风险导致贸易船只枪炮齐备，这成为17世纪海运业最显著的特征之一。这种情形在十八世纪的大部分时间里的某些海域仍可看到。1750年以前，在加勒比地区，尤其是牙买加附近，重达100吨以上的轮船几乎一直都全副武装，甚至小船通常也备有枪只。

私掠船巡航加剧了这一混乱局面。当时有个普遍的作法，即单一民族国家经常准许其公民袭击敌对国家的船只。签发这种私掠委任状或称特许状在战时不受限制，在和平时期也会偶尔向那些由于敌国行为而遭受损失的本国公民开绿灯。由于私掠船往往对特许状上的限制条款视而不见，因而一般说来很难把他们的所作所为与海盗行径区分开来。

政府的其它政策使当时的海上凶险加剧。除了私掠船巡航和海盗袭击，一些岛屿被刻意安置了被流放的罪犯。当然，海盗行为不仅限于加勒比地区。在北卡罗来纳入口处就有公然埋伏着的海盗，经常劫掠在查尔斯顿进行贸易的商船。1718有人抗议说：“每月都不断发生暴行：公海有船只遭劫，船货均被烧毁，或劫匪把船只扣留，无法无天地据为己有。”卡罗来纳当地的贸易商、承运商和政府官员一再恳求贸易委员会予以保护。情急之中，卡罗来纳州议会于1719年拨出款项资助私掠船以期把海盗逐出海域。这些请求与保护行动大都枉费心机，但由于保障贸易通道安全的益处超过了驱除海盗的耗费，最后英国皇家海军采取了行动。到18世纪40年代初，大西洋西海域的海盗已被铲除。

伴随着海盗覆灭的是轮船武装的解除与船员的削减。由此，技术扩散的过程得以进展。海盗不复存在以后，与快艇相似的专业载货船被设计出来，海运成本因此大大地降低了。

1. economic growth: 经济增长。指一国或地区的国民生产总值（GNP）或按人口平均的GNP值的增加，是以实际国民生产总值来衡量的。

2. technological change: 技术变革，类似的说法有technological advance/technological progress。

3. output relative to inputs: 即output-input ratio, 产出投入比率, 它是劳动生产率(productivity)的衡量指标。

4. 十九世纪初工业革命从英国扩展到美国，轧棉机、水轮纺织机、蒸汽机等技术的运用带动美国进入工业化时代。到了1860年，美国的制造业已仅次于英国。

5. cotton gin: 轧棉机，轧花机，用来把种子、种子壳和其他小东西和绵纤维分开的机器。由美国人Eli Whitney 发明。

6. steam power: 蒸汽动力，使用加压水蒸汽机器产生的动力，当时在美国用于铁器和玻璃制造。

7. many metallurgical advances: 1840年之后，金属机械技术的改进降低了蒸汽机的成本，提高了生产效率和可靠性。

8. 当时木炭是手工业的主要燃料，由于它很廉价，所以煤炭的使用相对缓慢。直到1830年以后，随着运输业的发展，煤炭才成为美国制造业的新能源。

9. work the forges: 操作锻造炉。

10. 17世纪北美殖民地造船业很兴盛，船坞遍布新英格兰海岸。当时金属材料缺乏，船坞与船只的建造以木材为原料，轮船的动力为机械能（人力与风力）。

11. Dutch shipping: 十六、十七世纪荷兰海运业发达，荷兰人被称为“海上马车夫”。1651年《航海条例》禁止用荷兰平底船运输北美殖民地的货物，从而促进了北美殖民地造船业的发展，使荷兰把持的海运业受到沉重打击。

12. manning: 配置船员，人员配备。

13. input requirements: 投入物需要量。

14. bulk commodities: 大宗商品，散装货（通常成本较低）。

15. 平底船在设计时没有考虑对付海盗的需要，船上没有武器装备、炮台及加固用的板条，所以轻巧简洁。

16. the Mediterranean: 地中海沿岸地区，包括法国、意大利、西班牙、葡萄牙等国。

17. the West Indies: 西印度群岛，位于北美洲东南部与南美洲北部的群岛，最初为哥伦布在1492-1504年的航行中发现并探索。第一个永久性的欧洲居民居住点由西班牙人于1496年在伊斯帕尼奥拉岛上建成。在殖民地时期，英国、法国和荷兰也对许多岛屿提出领土要求。

18. the Caribbean: 加勒比海，大西洋属海，位于南美大陆、中美地峡和大、小安的列斯群岛之间。

19. Jamaica: 牙买加，位于加勒比海沿岸的一个岛国。1494年由哥伦布发现，1509年西班牙在此实施殖民统治，1655年英国占领并于1670年正式吞并该地。1962年该国独立。

20. privateering: 以私掠船巡逻（私掠船为战时特准攻击敌方商船的武装民船）。

21. piracy: 海盗劫掠，未受任何主权国家委派的海上抢劫或从海上来到陆地上抢夺的行为。

22. 当初从英国到北美殖民地的移民中有许多囚犯，没被绞死而被流放他乡，此外还有流氓、流浪汉、娼妓、骗子等被英国所唾弃的人。

23. North Carolina: 北卡罗来纳（州），美国东南濒临大西洋的州。1789被承认为十三个创始殖民地之一。始建于1653年，为卡罗来纳省的一部分直到1691年。1711年成为一个分开的殖民地，1729年成为皇家殖民地。北卡罗来纳州1861年5月退出联邦，1868年被联邦重新认可。这个州长期为烟草种植地和加工地。

24. Charleston: 查尔斯顿，美国南卡罗来纳州的一个城市，从殖民地时期起就是一个重要的商业和文化中心。

25. high seas: 公海，一国领土管辖权以外的海洋的公共水域。

26. the Board of Trade: 1643年英国议会决定成立贸易委员会，负责殖民地及其贸易的管理，实际上是为了促进和保护英帝国的贸易利益。